Consider the following statements and select the correct answer from the codes given below: Assertion [A]: Aridity is the distinctive characteristic of the deserts. Reason [R]: They receive low rainfall and have high evaporation.

• 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.