Posterior part of the body refers to the back part. If you were to draw a line going down your body from the side separating your front half and back half anything in the front is called anterior anything in the back half is called posterior. Posterior is also referred to as dorsal. You can remember this by hi ok f about a dolphins dorsal fin (that is on their back). So.... your pecs would be In the front half (your chest).. Your biceps would be in the front half of your arm. Sarorious would be in the front half by your ribs.. However the triceps are on the back half of your arm. So D is the answer. Triceps are on the posterior portion of the body from the anatomical position.