The correct option is D sterile females
In a colony, there are 10,000 to 60,000 bees. But all of them do not collect nectar. There is a strict division of labour.
- The queen bees are fertile females which lay thousands of eggs.
- The drone bees are fertile males and their job is only to help in fertilizing the eggs laid by the queen.
- Worker bees are sterile females who do the actual work of collecting nectar.