The question asks to describe the transformation that occurred for the function $g(x) = f(x) - 1$.

This transformation involves a vertical shift. The rule $g(x) = f(x) - 1$ indicates that the graph of $f(x)$ has been shifted down by 1 unit.

Therefore, the correct answer is the "down 1" option.

Would you like more details on function transformations, or do you have any other questions?

Here are some related questions:

1. What happens when the transformation is $g(x) = f(x) + 1$?
2. How do horizontal shifts differ from vertical shifts in function graphs?
3. How would a transformation like $g(x) = -f(x)$ affect the graph?
4. What kind of transformation does $g(x) = 2f(x)$ represent?
5. How would the graph change if the transformation was $g(x) = f(x - 1)$?

Tip: When a constant is added or subtracted outside the function, it results in a vertical shift.