A Boat Travels at a Constant Speed with Respect to Still

Multiple Choice

A boat travels at a constant speed with respect to still water. Now suppose the water is moving with respect to the bank at a speed almost as large as the speed of the boat with respect to still water. Compare the time taken for a round trip of constant distance (with respect to the bank) in the boat under two scenarios: downstream, then upstream or cross-stream, then back. The "down-up" time is

A) larger than the "across-back" time.
B) equal to the "across-back" time.
C) less than the "across-back" time.