Answer:
the 4th answer I(x) = P(x-4)
Explanation:
the first 2 options are out, because just adding values to the functional result values changes the y value, and the curve is pushed up or down. but not to the side.
just imagine
I(x) = P(x-4) means that the function value of previously at x-4 happens now at x. 4 units "later" (or more to the right).
"x+4" would make the functional value at previously x+4 happen now at x. so, everything would shift to the left (happen "earlier").
therefore, the 4th answer option is correct.