We will wait ______ the signal becomes clear.

We will wait ______ the signal becomes clear.

• A. While
• B. After
• C. Before
• D. Until

Answer: (D)

Until is used to show that an action continues up to the moment another event happens. Here, we keep waiting right up to the moment the signal becomes clear, and then proceed. Using while would suggest doing the waiting and the signaling happening at the same time, which doesn’t set a boundary to the waiting. After would place the waiting after the signal is clear, which doesn’t match wanting to wait for that moment. Before would imply waiting earlier than the event, which also doesn’t fit the intended sequence. So this choice naturally expresses waiting up to the point when the signal is clear.

Until is used to show that an action continues up to the moment another event happens. Here, we keep waiting right up to the moment the signal becomes clear, and then proceed. Using while would suggest doing the waiting and the signaling happening at the same time, which doesn’t set a boundary to the waiting. After would place the waiting after the signal is clear, which doesn’t match wanting to wait for that moment. Before would imply waiting earlier than the event, which also doesn’t fit the intended sequence. So this choice naturally expresses waiting up to the point when the signal is clear.