Which of the following statement is correct?I. A boat can travel 30 km downstream in 6 hours. If it can travel 40 km upstream in 10 hours, then speed of stream is 1 km/hr.II. Length of a train is 1200 metre. If it can cross a 1500 metre long platform in 120 seconds, then speed of train is 90 km/hr.

• A. Neither I nor II
• B. Both I and II
• C. Only I
• D. Only II