What is the area between the abdomen and upper inner thigh called?

The correct term for the area between the abdomen and the upper inner thigh is the groin. This region is anatomically important as it serves as a transition area between the abdomen and the legs. It includes the inguinal region, where various structures such as blood vessels, nerves, and lymphatics pass from the trunk to the lower limbs.

The groin is also clinically significant; it is often associated with movements such as flexion and rotation of the hip, and it is a common area for injuries, particularly in athletes. While other terms like "pelvis" refer to a larger bony structure that houses the reproductive organs and is located higher than the groin, and "perineum" refers to the area between the anus and the genitals, these do not specifically denote the area directly in question. The "apex" does not refer to any anatomical area relevant to this context. Thus, the groin is the most accurate choice for the specified anatomical location.