To simplify the expression, we can use the rule of exponents that states when you multiply two numbers with the same base, you add the exponents. Therefore, we have:
4^(-8) / 4^(-7) x 4^0 = 4^(-8 + 7) x 4^0 = 4^(-1) x 4^0
Now, we know that any number raised to the power of 0 is equal to 1, so we have:
4^(-1) x 4^0 = 4^(-1) x 1 = 4^(-1)
Therefore, the expression is equivalent to 4^(-1).
The answer is A. 4^-1.