Many Worker Bees Give Their Lives to Save a Bee

Many worker bees give their lives to save a bee hive from an attack by bears or other animals.In such cases,we now know that

A) this is a case of sexual selection.
B) each female worker is waiting to get her chance to reproduce.
C) this is a case of bees consciously understanding the need to preserve the nest for their individual benefit-they might survive if all work together.
D) These worker bees will have a reproductive benefit if the members of the hive survive.