Question

the drill press speed should be adjusted: *
a) while running
b) only when off
c) at any time
d) by the instructor only

Explanation:

For safety, a drill press's speed must be adjusted when it's off. Adjusting while running (A) is dangerous. "At any time" (C) ignores safety. "By instructor only" (D) is too restrictive; users trained can adjust when off. So B is correct.

Answer:

B) Only when off