General Studies · Number Analogy

Two sets of numbers are given below. In each set of numbers, certain mathematical operation(s) on the first number result(s) in the second number, on the second results in the third, and so on. Which of the given options follows the same set of operations as in the given sets? (NOTE: Operations should be performed on the whole numbers, without breaking down the numbers into their constituent digits.) 3 - 9 - 12 - 24 4 - 16 - 20 - 40