What is unique about olfaction as compared to other special senses in terms of its neural transduction pathways to the cerebral cortex? (a: it does not first synapse in the thalamus like all other special senses). in addition to the olfactory cortex what other subcortical structures do olfactory pathways communicate with and how does this influence our perception of odors?

Gustation

Explanation:

It affects our perception of odors when we feel them in our mouth and we can "taste" them because both systems are connected and our brain can save the information of what we smell and taste as the same, even if we have only smelled something but haven't tasted it.

d. i assume the underlined word is "role." reformat if it isn't.

explanation:

role is closest to part because when replacing words, "playing a vital decision," "playing a vital activity," and "playing a vital dollar" don't make logical sense. the only meaningful choice is "playing a vital part."

this fits one of merriam-webster's definitions of role: "a function or part performed especially in a particular operation or process."