Bottom openings 15 cm × 15 cm in the standing baffle wall are provided A. 15 cm c/c B. 22.5 cm c/c C. 30 cm c/c D. 50 cm c/c

The correct answer is A. 15 cm c/c.

A standing baffle wall is a type of wall that is used to prevent the spread of fire. It is typically made of concrete or masonry and has a series of openings that allow for the passage of air. The openings are typically 15 cm × 15 cm in size and are spaced 15 cm c/c. This spacing ensures that the air flow through the wall is sufficient to prevent the build-up of heat and smoke.

The other options are incorrect because they do not provide the necessary spacing for the air flow through the wall. Option B, 22.5 cm c/c, would result in too much air flow, which could cause the wall to collapse. Option C, 30 cm c/c, would not provide enough air flow, which could allow the fire to spread. Option D, 50 cm c/c, would provide even less air flow than Option C, which would be even more dangerous.

Therefore, the correct answer is A. 15 cm c/c.