To determine the time of the last train to Lisbon, let's carefully analyze the provided information and convert the time given from the 24-hour format to the 12-hour format.
The last train departure time is given as 21:43. This is in the 24-hour format. To convert this time to the 12-hour format:
1. Identify the hour and minute from the 24-hour format:
- Hour: 21
- Minute: 43
2. Determine the period (a.m. or p.m.):
- Any time from 12:00 to 23:59 in the 24-hour clock is considered p.m.
- Since the hour is 21, which is greater than 12, the period is p.m.
3. Adjust the hour for the 12-hour format:
- Hours in the 24-hour format that are greater than 12 should be converted by subtracting 12.
- 21 - 12 = 9
So, 21:43 in the 24-hour format corresponds to 9:43 p.m. in the 12-hour format.
Based on the above conversion, the last train to Lisbon departs at 9:43 p.m. Hence, the correct option is:
9:43 p.m.
Therefore, the correct answer is:
Option 2: 9:43 p.m.