Final answer:
The least amount of effort is required when the body is lying down in a supine position, allowing for a relaxed and naturally aligned posture.
Step-by-step explanation:
The least amount of effort is required to accomplish a task when the body is in the supine position, which is lying down with the face up. When a person is supine, the body is in a relaxed state, aligning with the natural position, thereby reducing the effort needed to maintain posture. Good posture involves keeping the body's center of gravity directly above the pivot point in the hips to avoid strain, which is easier to maintain when lying down. Tasks that do not require standing or sitting can often be performed with less effort in the supine position, as it supports natural bodily functions and can minimize physical stress.