Final answer:
The thoracic duct does not collect lymph from the right arm; this task is handled by the right lymphatic duct.
Step-by-step explanation:
The thoracic duct, a major component of the lymphatic system, is responsible for collecting lymph from various regions of the body. It begins below the diaphragm in the cisterna chyli, receiving lymph from the lower abdomen, pelvis, lower limbs, left thorax, left upper limb, and the left side of the head. However, the thoracic duct does not collect lymph from the right side of the body.
Instead, this function is carried out by the right lymphatic duct, which drains lymph fluid from the right upper limb, right thorax, and the right side of the head. Therefore, the correct answer to the question of which area the thoracic duct does not collect lymph from is indeed C) Right arm. This distinction highlights the specialization and division of roles within the lymphatic system.