Direct: "Please place the helmets on the rack." Reported later: The instructor ___.
asked the riders to place the helmets on the rack✓Correct answer
asked to place the helmets on the rack before leaving
asked the riders place the helmets on the rack
asked that the riders to place the helmets on the rack
Explanation
Asked the riders to place the helmets on the rack supplies the required personal object and to-infinitive for the reported request. Asked that the riders to place is malformed because a mandative that-clause would use the base form place without to.