The correct answer is (d) 1960.
The decimal coinage system was introduced in India in 1960. The new system was based on the Indian rupee, which was divided into 100 paise. The old system, which was based on the British Indian rupee, was divided into 16 annas, each of which was divided into 12 pies.
The introduction of the decimal coinage system was a major change for India. It made it easier for people to do business and to understand the value of money. It also helped to modernize the Indian economy.
The following are the options of the question:
(a) 1951: This is incorrect because the decimal coinage system was not introduced in India in 1951.
(b) 1955: This is incorrect because the decimal coinage system was not introduced in India in 1955.
(c) 1957: This is incorrect because the decimal coinage system was not introduced in India in 1957.
(d) 1960: This is the correct answer because the decimal coinage system was introduced in India in 1960.