Assertion A : From consideration of structural soundness and economy of design, most codes control the maximum slenderness ratio of masonry walls and columns. Reason R : By controlling the maximum slenderness ratio, failure is by excessive stress and not by buckling. Select your answer according to codes given below:

• A. Both A and R is true and R is the correct explanation of A
• B. Both A and R is 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