The prefix "epi-" means what?

The prefix "epi-" derives from Greek and typically means "on" or "above." It is commonly used in various scientific and medical terms to denote a position that is situated on top of or above something else. For instance, in anatomy, "epidermis" refers to the outer layer of skin, indicating that it is located on top of the underlying layers. The use of "epi-" signifies a relationship to the surface or an outer structure, making it clear that this prefix implies being positioned atop something else.

The other choices represent different prefixes with distinct meanings. "Below" is denoted by "hypo-," which implies a location underneath another structure. "Alongside" is suggested by "para-," indicating a position adjacent to or alongside another entity. "Within" or "inside" is captured by "endo-," which refers to something located inside or internal to another structure. Each of these prefixes reflects a specific spatial relationship that is different from what "epi-" conveys.