According to the passage, diesel-towed barges differ from deep-water vessels in that they ______.
A) are less restricted in operation C) are larger shipments
B) are less flexible D) are most flexible

A．According to the passage, diesel-towed barges differ from deep-water vessels in that they ______.
B．are less restricted in operation
C．are less flexible
D．are larger shipments
E．are most flexible