It Is Rather Easy to Understand Why Relatives Help Each

It is rather easy to understand why relatives help each other in the animal kingdom-they share some of the same genes, and some self- sacrificing behaviour will help the greater sum of their genes. What would be a reason for self- sacrificing behaviour to have evolved in animals that are unrelated?

A) This behaviour might elicit a benefit at some future point in time.
B) This behaviour might have aided groups of unrelated animals.
C) This behaviour might have arisen due to genetic drift.
D) Answers A and B both apply.
E) Answers A and C both apply.