Answer:
The answer is c( to send signals to control the body)
Condensation is the process of watervapor in the air is changing into liquid water. Condensation is crucial to the water cycle because it is responsible for the formation of clouds. Condensation is also the opposite of evaporation
Due to it's electronic configuration w/c is 1s2 2s2 2ps 3s1 considering the last w/c is 3s1, sodium should be in row 3 period a1.
I think the answer for #3 is A not 100% sure but hope I can help!