For plastering the exposed brick walls, the cement sand mortar should be A. 1 : 2 B. 1 : 3 C. 1 : 4 D. 1 : 6

The correct answer is: A. 1 : 2

The cement sand mortar for plastering the exposed brick walls should be 1 part cement to 2 parts sand. This is the most common ratio used for plastering, and it provides a good balance of strength and workability.

A ratio of 1 : 3 would be too weak, and a ratio of 1 : 4 would be too stiff.

The cement sand mortar should be mixed with clean water until it has a smooth, workable consistency. It should be applied to the brick walls in a thin layer, and it should be allowed to dry completely before it is painted or sealed.

Here is a brief explanation of each option:

• Option A: 1 : 2 is the most common ratio used for plastering, and it provides a good balance of strength and workability.
• Option B: 1 : 3 would be too weak, and it would not provide enough strength to support the weight of the plaster.
• Option C: 1 : 4 would be too stiff, and it would be difficult to work with.
• Option D: 1 : 6 would be too weak, and it would not provide enough strength to support the weight of the plaster.