Which statement about a longitudinal study is true? a. study subjects are observed or measured just once. b. subjects in the study are all the same age. c. the study is relatively inexpensive. and. the study is over quickly.

It is true that subjects in the study are all the same age.

Option B

Explanation:

Longitudinal study is that type of study where the subjects in the study are of the same age and they normally have similar characteristics and normally experience similar events at a particular period of time.

This study involves observation of the people of the same group a number of times to observe a particular characteristics of that group. The study might be either long or short of the same variables. For example looking at the learning habit of children of group of students of five years.

d.) greenhouse gases

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