Social and emotional development include advancement of

a. fine and gross motor skills

b. feelings of self confidence and self worth
c. free expression of feelings such as frustration and excitement
d. lifelong friendships and good manners

D.) lifelong friendships and good manners

It's obvious that option A isn't the answer. Lifelong friendships and good manners won't be an advancement in social and emotional development. In this kind of development, option b or c could be correct but b won't exactly be an advancement. The most reasonable answer would be C. Free expression of feelings such as frustration and excitement.

i believe is was

answer; i believe that the correct answer is (b) is a factor associated with physical activity and heart disease;