Tom wants a candy bar and is trying to decide between a crunch, a snickers, or a mily way. these three candy bars are in tom' .

evoked set

Explanation:

Evoked set

The group or the collection of the possible brand of items , the consumer or the buyer is narrowing down , out of all the other products , These selected brands or items are characteristic as the Evoked set .

These brand could be the well trusted or most familiar brands and which immediately comes on the mind of the customer .

Hence , in this case , Tom is short listing from a selected brands to decide his candy bar .

since you have not provided the options here i   am going to give you general overview about hormone.hormone are actually the part of endocrine system in our body and produced by the endocrine glands. the hormones act like a chemical messenger   within human body. once produce by the glands they   travel through the blood stream and reach at specific or target tissue and organs   which result in control of our body function. the hormones are specific in their work and work on only the targeted tissue or organ   . with the of hormone endocrine system regulate the heart rate , metabolism, our mood and   growth as well as the development and even the sleeping cycle etc. they actually are the messenger for body cell and organs .