The vessel that carries blood to the left arm is known as which of the following?

The left subclavian artery is the arterial vessel responsible for supplying blood to the left arm. It branches off from the aortic arch and travels laterally to reach the left arm. This artery is crucial for providing oxygenated blood that is necessary for the functioning of the left upper extremity.

In contrast, the descending aorta, which is the main artery that carries blood from the heart through the thoracic and abdominal areas, does not specifically direct blood to the left arm but rather continues to supply lower regions of the body. The inferior vena cava is a major vein that collects deoxygenated blood from the lower body and returns it to the heart, which also does not supply blood to the left arm. The pulmonary artery is responsible for carrying deoxygenated blood from the heart to the lungs for oxygenation, therefore it is unrelated to the supply of blood to the arms.

Understanding the specific role of the left subclavian artery in upper limb circulation clarifies why it is the correct answer in this context.