Which of the following is a part of the lower limb?

The crural region is indeed a part of the lower limb, specifically referring to the area of the leg between the knee and the ankle. This region encompasses the shin and is important for various functions such as walking, running, and bearing weight. Understanding the anatomical divisions of the body helps in identifying the specific parts and their functions.

In contrast, the thoracic region pertains to the upper part of the trunk, including the chest; the cranial region refers to the head and the skull; and the abdominal region encompasses the area between the chest and the pelvis, containing organs essential for digestion and other bodily functions. None of these regions are associated with the lower limb, making the crural region the correct choice.