What is the length of a running train crossing another 180 metre long train running in the opposite direction? I. The relative speed of the two trains was 150 kmph. II. The trains took 9 seconds to cross each other.

• A. I alone sufficient while II alone not sufficient to answer
• B. II alone sufficient while I alone not sufficient to answer
• C. Either I or II alone sufficient to answer
• D. Both I and II are not sufficient to answer
• E. Both I and II are necessary to answer