Final answer:
The true statement about beta-carotene is that its bioavailability is increased by heating. It is a provitamin converted into vitamin A in the body and is derived from plant sources.
Step-by-step explanation:
The correct answer to the question "Which of the following is true of beta-carotene?" is option a. Its bioavailability is increased by heating. Beta-carotene is known as a provitamin because it can be converted into vitamin A in the body. The absorption and utilization of beta-carotene are facilitated when foods containing it are cooked, which helps release the beta-carotene from the food matrix and increases its bioavailability. Beta-carotene is not a nonprovitamin A carotenoid; it is, in fact, the most potent precursor of vitamin A. Lastly, it cannot be synthesized from retinoic acid; instead, it is a plant-derived precursor that the body converts to vitamin A.