Answer:
c. students would purchase more than 750 cups per day.
Explanation:
As per the law of demand, an inverse relationship exists between price of a good and it's demand. If price of a good falls, keeping other factors affecting demand as constant, the quantity demanded of the good shall rise.
In the given case, quantity demanded of coffee is 750 cups per day at the price level of $4.25 per cup. When price falls to $3.75 per cup, the demand for coffee shall now rise. So ideally, more than 750 cups shall be purchased by students now.