9514 1404 393
Answer:
A. 2
Explanation:
When you don't know if a number like 256 is a power of anything, it can work reasonably well to start by simply dividing by the factors you know.
- 256/2 = 128
- 128/2 = 64
- 64/2 = 32
- 32/2 = 16
- 16 = 2^4, so 256 = 2^4 · 2 · 2 · 2 · 2 = 2^8
The 8th root of 2^8 is 2, choice A.