The question asks:

If $f$ is a function with the property that $f(-x) = f(x)$ for all values of $x$, which statement must be true?

This property $f(-x) = f(x)$ defines an even function. A function is even if its graph is symmetric about the y-axis. Based on this definition, we can conclude that the correct answer is:

A. The graph of $f$ is symmetric to the y-axis.

Would you like further details, or do you have any questions?

Here are 5 related questions for further practice:

1. What is the definition of an odd function?
2. How do you determine if a function is symmetric about the origin?
3. Can a function be both even and odd? Explain why or why not.
4. What is the graphical interpretation of the inverse of a function?
5. How do transformations affect the symmetry of a function?

Tip: Even functions have symmetry about the y-axis, while odd functions have symmetry about the origin.