Answer:
c
Step-by-step explanation:
Only f(x) = π cos(πx) accounts for the correct results.
To varify, you need to substitute x for the value given in f(x).
f(1/2) = π cos(π * 1/2) and this result is 0
simularly...
f(2) = π cos(π * 2) and this result is π
So answer c is correct.