The function f(x) = 8(1/4)^x is reflected across the y-axis to create g(x). which table of values could be used to graph g(x)?

It's the first one.

To reflect the function  about the y-axis, we write. 

You can then substitute values into both functions. Remember that something to the power zero is equal one, so for either function evaluated at x = 0, the answer is 8.