The x-values in the table for f(x) were multiplied by -1 to create the table for g(x). what is the relationship between the graphs of the two function.

The graph of f is reflected across the y-axis to create the graph of g. (C)

You are basically assigning the same y-value to the opposite x-values to make g(x). So, for the point (x, 31), on f(x), x is -2, but on g(x), x is 2. Thinking about this visually, you can imagine that this represents a reflection of f across the y-axis.

(Side note: Later in math, this symmetry will be formalized so that you can find it algebraically. It's called "even" symmetry.)