Which Latin phrase indicates a trade or exchange?

The Latin phrase that indicates a trade or exchange is "Quid pro quo." This expression literally translates to "something for something," embodying the concept of a reciprocal arrangement where one thing is given in exchange for another. It is commonly used in legal, business, and everyday contexts to imply that a mutual exchange is occurring, emphasizing the idea of an equal trade.

The other phrases, while significant in their own contexts, do not relate to the idea of exchange. "Curriculum Vitae" refers to a summary of a person's education and work experience, "Alter Ego" denotes a secondary or alternative personality, and "Ad Hoc" refers to something created for a specific purpose or situation. Thus, "Quid pro quo" is the correct choice for indicating a trade or exchange because it directly captures the essence of reciprocity in various situations.