Consider the following statements and select the correct answer from the code given below: Assertion [A]: The circum-pacific belt is the most vulnerable zone of Tsunamis. Reason [R]: It is tectonically most active area and generates weld's major earthquakes.

• 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.