What would happen if a 14 year old average girl only eats 100 calories a day? Will she lose weight and if so how many?

no

Explanation:

100 calories is not nearly enough for a growing body, therefore her body will store as much fat as it can from what she does eat because it isnt sure when its next meal will come, so starving yourself doesnt help lose weight, you'll just gain. i know first hand :(

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.