Answer:
a. thoracic duct
Explanation:
Trunks drain into ducts. Therefore only ducts drain into the bloodstream. The answer can be either option a or b.
Why a? The thoracic duct allows lymph from the left side of the body and the limbs (left and right side) to drain into the bloodstream. The right lymphatic duct drains fluid from the upper regions of the body, the right side, right arm and the head.
