Final answer:
c. Giving up an existing legal right or taking on a new legal duty.
Legal detriment refers to either giving up a legal right or taking on a legal duty in exchange for a contractual promise, which is a cornerstone of contracts enforceability that supports economic transactions and growth.
Step-by-step explanation:
"Legal detriment" in the context of consideration means c. Giving up an existing legal right or taking on a new legal duty. In contract law, consideration is a fundamental principle that refers to something of value, which is given in exchange for a contractual promise. The concept of legal detriment involves either the act of doing something one is not legally obligated to do or refraining from doing something that one has a legal right to do. An example is an employment agreement where a surgeon expects to be paid after performing a surgery. The contractual rights based on property rights provide the surgeon the legal recourse to seek payment through the legal system if not paid, highlighting the enforcement of contracts as crucial for economic transactions and growth.