You take a sip of coffee, and it's too hot. the of your receive this stimulus

When you take a sip of coffee, and it's too hot. the dendrites of your sensory neurons receive the stimulus. 
Sensory neurons are nerve cells within the nervous system responsible for converting external stimuli from the organism's environments into internal electrical impulses. They correct information from sensory receptors which are then passed on to the CNS for further processing by afferent neurons. 

Well i had the same answer, so the correct answer would be a. but in this case it would be the one with plasma membrane and cell wall circled that is next to the hairy pill type of thing.