For this case we have the following function:
f (x) = 5 * (1/3) ^ x
We must evaluate the function for x = 4
We have then:
f (4) = 5 * (1/3) ^ 4
Rewriting:
f (4) = 5 * (1/81)
f (4) = 5/81
Answer:
The function evaluated at x = 4 is:
f (4) = 5/81
option C