Final answer:
The Valsalva maneuver increases venous return by forcibly increasing chest pressure and compressing venous systems to push blood back to the heart. Quiet breathing or transitions from supine to standing do not have the same effect. Vasoconstriction also plays a role in enhancing venous return.
Step-by-step explanation:
A maneuver that will increase venous return is C. Valsalva maneuver. This maneuver involves a person trying to exhale forcibly with a closed mouth and nose, which results in increased pressure in the chest cavity and subsequent compression of the venous system. It effectively 'squeezes' the veins, which pushes blood back towards the heart, increasing venous return. The other options, like transitioning from supine to standing or standing to walking, may have varying effects on venous return but do not directly increase it in the way the Valsalva maneuver does. Quiet expiration, on the other hand, occurs during quiet breathing and does not actively increase venous return; rather, normal respiratory functions continue to maintain regular blood flow.
Vasoconstriction also increases venous return, affecting blood pressure within the vein, blood flow within the vein, and consequently, the return of blood to the heart. It is important for the proper functioning of the circulatory system.