D. Stereotype. Hope this helps :)
Running after school
Exercise and other physical activity produce endorphins—chemicals in the brain that act as natural painkillers—and also improve the ability to sleep, which in turn reduces stress.
Chris's attitude change is best explained by cognitive dissonance.
It refers to the fact that a person may be experiencing thoughts and feelings which are not really consistent, and which may change, sometimes drastically. In Chris's case, he hated pop music, until he actually listened to one pop song and liked it, and then changed his opinion.
Answer: (A) Efficiency
Explanation:
According to the given question, Nate is start learning swimming and he needs improvement based on his efficiency as it is the ability for producing the desirable result by avoiding all the negative circumstances.
As, Nate always splash water on lifeguard during the swimming so that is why he improves his performance more efficiently.
The efficiency is the process that reduce or avoid all the unnecessary resources like physical material and helps in achieving the high result. Therefore, Option (A) is correct.