Assertion A : Depth and width required at the entrance to a harbour are more than those required in the channel. Reason R : The entrance to a harbour is usually more exposed to waves as compared to the harbour itself__________________?

Select your answer based on the coding system given below.
A. Both A and R are true and R is the correct explanation of A.
B. Both A and R are true but R is not the correct explanation of A.
C. A is true but R is false.
D. A is false but R is true.