Two students studying physiology taste a known "bitter" substance,and both report sensing bitterness.They then sample another substance.Student A reports sensing both a bitter taste and a salty taste,but student B reports only a salty taste.What is the most logical explanation?

A)Student A had an allergic reaction to the food, causing him to perceive the food as being bitter.
B)Student A has normal "bitter" taste buds; student B has defective "bitter" taste buds that result in lower sensitivity to bitterness.
C)Student A has a protein receptor capable of detecting a bitter molecule found in that substance, whereas student B lacks that particular protein receptor.
D)Student A has normal saliva, whereas student B's saliva is more alkaline than normal.
E)Student A has fewer umami receptors than student B.