Consider Two Organisms, X and Y, Which Are Involved in a Type

Consider two organisms, X and Y, which are involved in a type of ecological interaction. Which of the following statements is false?

A) If X and Y are mutualists, both organisms have a positive effect on the growth of the other.
B) If X is a commensal organism on Y, X has a positive effect on Y, but Y has no effect on X.
C) If Y is a commensal organism on X, X has a positive effect on Y, but Y has no effect on X.
D) If X and Y are competitors, both organisms have negative effects on each other's growth.
E) If X is a predator and Y is prey, X has a negative effect on Y, but Y has a positive effect on X.