The primary reason to buy a whole pork loin instead of a boneless loin is:
B) It costs less per pound.
Buying a whole pork loin typically allows you to get more meat for your money compared to purchasing a boneless version, which is often processed and may include labor costs in the price. Additionally, options A, C, and D may vary based on specific cuts, methods of preparation, and cooking, but generally, the cost-effectiveness is a significant reason for purchasing the whole loin.