In MS-Excel output of SUMSQ (1, 2, 3) is :

The correct answer is (a) 12.

SUMSQ is a function in MS-Excel that returns the sum of the squares of the arguments. In this case, the arguments are 1, 2, and 3. The square of 1 is 1, the square of 2 is 4, and the square of 3 is 9. The sum of these squares is 12.

Option (b) is incorrect because it is the sum of the arguments, not the sum of the squares of the arguments. Option (c) is incorrect because it is the square of the sum of the arguments, not the sum of the squares of the arguments. Option (d) is incorrect because it is the sum of the squares of the arguments plus 1, not the sum of the squares of the arguments.