The answer is C. 75.
Explanation: Let’s go from smallest to largest.
A, 25, would not work because you can’t multiply 15 by a whole number to get 25.
B, 50, doesn’t work because again, you can’t multiply 15 with a whole number to get 50.
C, 75, is the CORRECT ANSWER because 5x15 is 75, 25x3 is 75, and 15x5 is 75. Each number can be multiplied by a whole number to get 75.