Final answer:
The abbreviations correspond to medical directives for administering medication, with 'ac' meaning before meals, 'bid' twice a day, 'pc' after meals, 'tid' three times a day, 'qid' four times a day, and 'PO' by mouth.
Step-by-step explanation:
The abbreviations from the question match the following meanings:
- ac - before meals
- bid - twice a day
- pc - after meals
- tid - three times a day
- qid - four times a day
- PO - by mouth
These abbreviations are commonly used in medical prescriptions to indicate the frequency and timing of medication doses.