The brain is fully developed
a. at the onset of adulthood.
b. in the fetus.
c. in the newborn.
d. at birth.

i got pantsed in the second grade

explanation:

out of the choices i'd say d the ability to set goals, mainly because to desire to continue you need motivation but it isn't motivation in that part, but setting goals means you have an endgame and you want to reach it which sums up motivation.