The answer is B. I hope this helps
X=4 is the answer if you are looking for x
The formula for this is

. If the diameter is 8 the radius is 4, so filling in accordingly we have

and

which is

and when you multiply in 3.14 you get that A = 401.92 or B above.
Answer:
The error is the exponent in the answer should be 11.
Step-by-step explanation:
When you move the decimal place one spot as they do in the final step to move it from a base 10 to a base 1, we have to add a exponent on. Therefore, it should go from 10 to 11.