Studies of college students have seen that low energy level is associated with low grades, but very high energy levels are also associated with low grades. Students with a general arousal level tend to have the most reliably good grades. This is an example of . a. Motivation
b. Yerkes-Dodson Law
c. Drive-reduction theory
d. Incentives

no , per capita income is not a true measure of the development because: -it only tells us about average income not how income is distributed among the people.it only give us an idea of the economic aspect.it is only at the qualitative basis.moreover, income is not only the way of development other factors are also as much as important as income.

fertile good for trade etc

the correct answer is a

answer; basic psychology;