Simplify:

8^3*8^6
A. 64^9
B. 8^9
C.8^18
D. 1152

To simplify the expression 8^3 * 8^6, we can add the exponents since we are multiplying two powers with the same base.

= 8^(3+6)
= 8^9

Therefore, the simplified expression is 8^9.

So, the answer is B.