The correct answer is option 2: 1975. Aryabhatt, the first Indian satellite, was launched in the year 1975.
Option 1: 1972 is incorrect because Aryabhatt was launched later than that year.
Option 3: 1976 is also incorrect because the correct year is 1975.
Option 4: 1979 is incorrect as well because Aryabhatt was launched before that year.
Therefore, the correct answer is option 2: 1975. The launch of Aryabhatt marked a significant milestone for India in the field of space exploration and technology. It was named after the ancient Indian mathematician and astronomer, Aryabhata.