Please read the passage and the questions under it carefully and Choose the correct answer A, B, C or D. (only one answer is correct)

Over 3000 years ago in Mesopotamia1 near the Persian Gulf, the Sumerians created an extensive society with a sophisticated level of culture. Sumerian writing originated around 3200 – 3100 BC and, together with early Egyptian hieroglyphs, provides, the earliest known system of writing. The principal function of Sumerian writing was to facilitate business transactions and accounting when these dealings reached a level of complexity too great to be entrusted to human memory alone.

Unlike the Egyptians in the Nile delta, the Sumerians had ho papyrus, which requires a marshy water-logged environment in which to grow, and stone was in short supply, so their written records were made in wet clay with a wooden wedge-shaped stylus. By changing the orientation of the wedge, different shapes could be impressed, and this diversity could be exploited to associate distinct meaning to different-shaped marks. The clay was then baked hard or left in the hot sun to create a semi-permanent inscription. These tablets are called cuneiform texts (the Latin cuneus means ‘wedge’), and thousands of these have been found which contain extensive arithmetical calculations.
The Sumerians did something that was both strange and unique amongst human counting systems. First, they followed their oral tradition of counting, with steps at 5,10 and 20, counting up to 50 using words which denoted the combinations. But after 59, 60 is taken as a new unit and termed gesh, which is the same as the word for ‘one’ which started the whole system off. Larger numbers were denoted by both multiples and products of sixties. Why was 60 selected to play this pivotal role in the counting system and labelled In the same way as the number ‘one’? The evidence for any viewpoint is circumstantial..

It appears that the early Sumerian systems of weights and measures contained standard reference qualities which were in the ratio of 60 to 1. Later, this structure seems to have been taken over into the more general number system that was used for all the forms of counting. But this still tells us nothing about why the first measures incorporated the factor 60.
Historians have considered possible astronomical motivations. An early belief that the year was made up of 360 days, dividing into twelve lunar months each of thirty days’ duration, might have played a role. Alternatively, it has been suggested that the earliest Mesopotamian calendars were based upon a zodiac of only six constellations which would then divide the year into six periods of sixty days’ duration.

The importance of sixty would be underlined by the fact that it represented the interval of time which the Sun spent in each of the constellations of the zodiac. Another proposal has been that the significance of 60 emerged from geometrical knowledge about dividing a circular area into six equal parts by drawing lines through the centre. But it seems more likely that such a procedure was derived from the perceived importance of the number 60.

Despite the peculiarity of the 60 unit, its presence is still evident in our own systems of measurement. Angular measure uses 60 seconds of arc to one minute, 60 minutes to 1 degree and 360 degrees around the circle. Navigational positions are fixed by this system through the specification of latitude and longitude. Our measures of time in terms of minutes and seconds are based upon the very same circular system. All this suggests that at one time sixty may have had a special status in the hierarchy of numbers.