why might a 24-hour independent grocery shop have a different gross margin to a regular grocery shop that opens from 8:00 AM to 8:00 PM? a) the 24 hour independent grocery shop will have a higher insurance and salary costs because of its extended hours, which will result in lower gross margin than the independent grocery shop b) an independent grocery shop will be able to purchase merchandise at a greater discount resulting in higher gross margin than the regular grocery shop c) the 24 hour grocery shop is able to charge premium prices and earn higher gross margin because consumers are generally willing to pay higher prices for the convenience of shopping at anytime