Which of the following is a prefix for "two like parts of a pair"?

The concept of a prefix that indicates "two like parts of a pair" leads us to "para-," which is derived from Greek and typically means "beside," "near,” or "alongside." In medical terminology and anatomical contexts, "para-" often describes situations involving asymmetric structures or pairs that are parallel or adjacent in relation to one another. For example, "parathyroid" refers to glands that are adjacent to the thyroid gland.

In contrast, the other prefixes provided each hold different meanings that do not align with the concept of "two like parts of a pair." For instance, "post-" signifies something that comes after or behind. "Nulli-" conveys the meaning of none or absence, often used in medical terms such as "nullipara," which refers to a woman who has never given birth. "Primi-" indicates the first in a series, as seen in the term "primigravida," which describes a woman who is pregnant for the first time. Therefore, "para-" best fits the description of two parts that are similar or associated closely in function or position.