The correct answer is A) 17
Why? Let's see ---
If an exponent means to multiply the base as many times as the exponent says, let's start with that.
3 x 3 x 3 x 3 = 81
4 x 4 x 4 = 64
Now we subtract each answer from each other -
81 - 64 = 17
↑ ↑ ↑ Hope this helps! :D