How and where is nectar unloaded by foragers upon their return to the hive?
a. by trophallaxis with receiver bee;
b. near hive entrance direct regurgitation into nectar cell;
c. upper area of wax comb direct regurgitation into nectar cell;
d. lower middle area of wax comb by trophallaxis with receiver bee;
e. upper area of wax comb.

The correct answer is option a. "by trophallaxis with receiver bee".

Explanation:

Bees collect nectar from flowering plants, and when nectar foragers return to their colonies, they unload the nectar by trophallaxis with receiver bee. Trophallaxis is defined as the interchange of regurgitated liquids between insects, this is the process that occurs between the foragers and the receiver bees once they give the collected nectar to the hive.