Help please question 8

The left ventricle in the heart chamber has the thicket walls

Explanation:

Although the left and right ventricle are similar in structure the walls on the left ventricle are thicker and stronger.

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.