Charles Darwin Was Initially Puzzled by the Observation That Worker

Charles Darwin was initially puzzled by the observation that worker honeybees die when they sting an intruder to their hive (the bee's stinger is ripped from the bee's abdomen, causing a fatal injury) . Based on what you know about natural selection, why did this observation complicate Darwin's theory?

A) All defensive behaviors in nature result in the death of the defender.
B) Such self-sacrifice is widespread in many different groups of animals.
C) He found it hard to imagine how such behavior could evolve, since a defending worker's chance of survival is zero.
D) The stinging apparatus appeared to be too complex to have evolved.