A driver is hauling a smooth bore milk tanker and says the lack of baffles means the cargo will not surge. What is wrong with that statement?

1. Smooth bore tanks have no internal structures to slow liquid flow, so forward-and-back surge is very strong
2. Milk is a solid cargo under CDL rules
3. Baffles are required in all food-grade tanks
4. Smooth bore tanks can only be driven empty