A Man Complains to His Doctor That He Has a Very

A man complains to his doctor that he has a very hard time smelling things. What could be the cause of this patient's poor sense of smell?

A) His olfactory sensory neurons lack chemosensitive hairs.
B) He has insufficient mucus production in his nasal cavity.
C) His olfactory-associated interneurons cannot fire action potentials.
D) Connections may not have developed between his olfactory-associated interneurons and sensory neurons.
E) All of these choices are correct.