Answer:
In the image is the first, fourth and last answer.
Explanation:
A function f is odd when is verified the condition (let x be the variable):
-f(x) = f(-x)
The equation of the fourth answer is f(x) = -x^3
so if you check the condition you'll have this as result:
-f(x) = x^3 = -(-x)^3 = f(-x). ✓
The condition is verified so the function is odd.
For the second and last answer it's the same process (try to verify if the function is odd by yourself using the given description above :) ).