x is the standard deviation of the set of numbers (a,b,c,d,e). For each of the following sets, indicate which sets must have a standard deviation equal to x.

(a+2, b+2, c+2, d+2, e+2)

(a-2, b-2, c-2, d-2, e-2)

(2a, 2b, 2c, 2d, 2e)

(a/2, b/2, c/2, d/2, e/2)