Answer:
13
Explanation:
They are vitamins A, C, D, E, K and the B vitamins (thiamine, riboflavin, niacin, pantothenic acid, biotin, vitamin B-6, vitamin B-12 and folate). You can usually get all your vitamins from the foods you eat.
Human behavior which can be seen by other people and observed by other people is usually also the behavior which is often subject to measurement, control, and experimentation in psychological experiments. The field which does this is psychology.
