The stretcher bond in brick masonry can be used only when the thickness of wall is A. 90 mm B. 180 mm C. 190 mm D. 280 mm

The correct answer is: B. 180 mm.

Stretcher bond is a type of brick masonry in which all the bricks are laid in the same direction, with their long sides exposed. This type of bond is used for walls that are not load-bearing, as it does not provide as much strength as other types of bonds. The minimum thickness of a wall laid in stretcher bond is 180 mm.

Option A is incorrect because the minimum thickness of a wall laid in stretcher bond is 180 mm, not 90 mm.

Option C is incorrect because the minimum thickness of a wall laid in stretcher bond is 180 mm, not 190 mm.

Option D is incorrect because the minimum thickness of a wall laid in stretcher bond is 180 mm, not 280 mm.