Choice Ahoice B is the correct answer.

1. Start with the equation: $8x + 16 = 64$
2. Subtract 16 from both sides: $8x = 64 - 16$
3. Simplify: $8x = 48$
4. Divide both sides by 8: $x = \frac{48}{8}$
5. Simplify: $x = 6$
6. Verify: $8(6) + 16 = 48 + 16 = 64$ ✓

Choice Ahoice D is incorrect because this results from adding 16 to 64: $80$, then $80/8 = 10$. Wrong inverse operation.

Choice Ahoice C is incorrect because this is the value of $8x$. You need to divide by 8.

Choice Ahoice D is incorrect because this results from multiplying 48 by 8: $384$.