Final answer:
For VFR flight by day in a control zone, the minimum visibility is 3 miles, with a cloud clearance of 1 mile horizontally and 500 feet vertically.
Step-by-step explanation:
When flying VFR (Visual Flight Rules) by day in a control zone (CTR), the minimum allowable visibility is 3 miles, while the minimum horizontal distance from cloud is 1 mile, and the minimum vertical distance from cloud is 500 feet. Therefore, the correct answer to your question is d) 3 miles, 1 mile, 500 feet.