Which abbreviation indicates that a medication should be taken before meals?

The abbreviation "ac" stands for "ante cibum," which is a Latin phrase meaning "before meals." This designation is commonly used in medical and pharmaceutical contexts to instruct patients to take medication before eating food. Taking certain medications before meals can enhance their absorption and effectiveness or decrease potential gastrointestinal side effects that might occur when taken with food.

In contrast, "pm" indicates that a medication should be taken in the afternoon or evening, and "hs" means "at bedtime," which conveys a different timing of administration. "qod" stands for "every other day," which references a frequency of dosage rather than a timing in relation to meals. Thus, "ac" is the appropriate choice for medications required to be taken before meals.