Correct Response: D. Because students are moving quickly and focused on the ball and other players during a game, a narrow safety zone risks the possibility of students crossing the end line moving at a speed too great to be able to stop before running into the wall. An emergency phone on the wall does not present a significant physical obstruction and would be a valuable safety precaution (A). A pile of mats outside the baseline would cushion any inadvertent contact and present no safety issue unless they are so close to the baseline they present a tripping hazard (B). One nonfunctioning light is not a safety hazard if other lights are working and the court is adequately lit for use (C).