Since the expressions for f(x) and g(x) are already given, f(g(2)) means to substitute the value of 2 to the expression of g(x), then further substituting the obtained value of g(2) into the expression of f(x). This is shown below:
f(x) = x + 8
g(x) = x^2 - 6x - 7
f(g(x) = x^2 - 6x - 7 + 8
f(g(2)) = 2^2 - 6(2) + 1
f(g(2)) = 4 - 12 + 1
f(g(2)) = -7
Therefore, the correct answer is -7.
