What is one main function of nervous tissue? communication between the brain and the rest of the body
contraction of muscles that results in movement
transportation of fluids throughout the body
protection of organs from the environment

communication between the brain and the rest of the body

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.