Playground projections should not increase in diameter in which direction?

Projections from playground equipment should not increase in diameter away from the surrounding surface in order to maintain safe and consistent play space for children. Increasing the diameter in any other direction could create risks for injury or disrupt the intended use of the playground equipment. Options A and C both suggest a larger and potentially imbalanced structure, while option D implies a rotational increase that also would change the structure and potential risk factors. Therefore, option B is the best answer choice as it specifically addresses the direction that would be most hazardous for playground projections to expand in terms of safety and functionality.