Changing the exponent by 1/2 ( going from x to 1/2x)
This does not change the y-intercept.
It does sharpen the curve, which means the y value does not increase as quickly when x is increased.
THe 3rd choice is correct.
Proof: make x=2
Y = 3^2 = 9
Y = 3^1/2(2) = 3^1 = 3
You can see y is smaller with the 1/2 included.