‘x’ is an input to a program to calculate the square of the given number. The range for

‘x’ is from 1 to 100. In robustness testing, which are valid inputs?

(a) 0, 1, 2, 50, 99, 100, 101

(b) 0, 1, 2, 3, 99, 100, 101

(c) 1, 2, 3, 50, 98, 99, 100

(d) 1, 2, 50, 99, 100