A(n) is a mental representation used for a variety of cognitive functions, including memory, reasoning, and using and understanding language.

a. exemplar
b. concept
c. unit
d. prototype

b. concept

Explanation:

In cognitive psychology, a concept refers to a mental grouping of similar things, events and people that is used to remember and understand what things are, what they mean, and the groups they belong to. This mental grouping will later be used for different other processes such as memory, reasoning and communicating with others.

Therefore, a concept is a mental representation used for a variety of cognitive functions, including memory, reasoning, and using and understanding language.

hygrometers and hair thermometers (often found as part of hygrometers/psychrometers) can be used to measure humidity. barometers are used to measure atmospheric pressure, while anemometers are used to measure wind speed. so the 2nd and 4th choices should be the correct answers.

well 1 they have there leader that controls them