contestada

If the domain of f(x) is [-5,8], what is the domain of the function y = f(x+2) -1 ?
a) [-7,6]
b) [-3,9]
c) [-4,6]
d) [-7,7]
e) [-3,10]

I figured that the answer was d, however the answer key states that it is a. Can you explain why?