Final answer:
The correct synonym for posterior is dorsal, which both describe the back or direction toward the back of the body. Dorsal is associated with the posterior body cavity that houses the brain and spinal cord.
Step-by-step explanation:
The term posterior refers to the back or direction toward the back of the body. In anatomical terms, posterior is synonymous with dorsal. The options provided are all anatomical directional terms, but the correct synonym for posterior in this context is dorsal, which describes the back or direction toward the back of the body. This is consistent with the definition that the posterior body cavity, also known as the dorsal cavity, houses the brain and spinal cord, indicating the back portion of the body. Therefore, the final answer is B: dorsal.
Other terms like distal and proximal relate to the distance from the point of attachment; inferior (or caudal) refers to a position below or lower than another part of the body; and superior (or cranial) is above or higher than another part. Ventral is synonymous with anterior, not posterior.