A boat takes 0.5 h more to travel a distance of 45 km upstream than to travel the same distance downstream. If the speed of the boat in still water is 4 times the speed of the stream, then in what time will it cover a distance of 72 km downstream?

• A. \(1 \frac{2}{5}\)h
• B. \(2 \frac{1}{6}\)h
• C. \(2 \frac{1}{3}\)h
• D. \(1 \frac{1}{5}\)h