Don’t hurry. The train won’t leave . . . . . . . . 5.50. A. until B. for C. in D. by

The correct answer is: until.

The word “until” is used to indicate a point in time before which something will or will not happen. In this case, the train will not leave until 5:50. This means that the train is currently still at the station and will not depart until 5:50.

The other options are not correct because they do not indicate a point in time. The word “for” is used to indicate a period of time during which something happens. The word “in” is used to indicate a point in time at which something happens. The word “by” is used to indicate a point in time before which something must be done.

Here are some examples of how the other options could be used in a sentence:

• The train will leave for Chicago in 30 minutes.
• The train will arrive in Chicago at 10:00 AM.
• The train must arrive in Chicago by 10:00 AM.