Answer:
C.
Explanation:
So, here's what you need to remember:
If we have a function f(x) and a factor k:
k(f(x)) will be a vertical stretch if k is greater than 1, and a vertical compression if k is greater than zero but less than 1.
f(kx) will be a horizontal compression if k is greater than 1, and a horizontal stretch if k is greater than zero but less than 1.
We are multiplying 0.5 to the function. In other words: 0.5f(x).
This is outside the function, so it's vertical.
0.5 is less than 1, so this would be a vertical compression