Sure, let's analyze the hourly traffic pattern to determine when a traffic officer intervention is required. According to the problem, if more than 17 cars are held up at the intersection during any given hour, a traffic officer will intervene. Here is the given hourly traffic data:
1. 12:00 p.m. - 01:00 p.m.: 16 cars
2. 01:00 p.m. - 02:00 p.m.: 24 cars
3. 02:00 p.m. - 03:00 p.m.: 6 cars
4. 03:00 p.m. - 04:00 p.m.: 21 cars
5. 04:00 p.m. - 05:00 p.m.: 15 cars
6. 05:00 p.m. - 06:00 p.m.: 24 cars
7. 06:00 p.m. - 07:00 p.m.: 9 cars
8. 07:00 p.m. - 08:00 p.m.: 8 cars
9. 08:00 p.m. - 09:00 p.m.: 9 cars
Next, let's identify the hours when the number of cars exceeds the threshold of 17:
1. 12:00 p.m. - 01:00 p.m.: 16 cars (No intervention needed)
2. 01:00 p.m. - 02:00 p.m.: 24 cars (Intervention needed)
3. 02:00 p.m. - 03:00 p.m.: 6 cars (No intervention needed)
4. 03:00 p.m. - 04:00 p.m.: 21 cars (Intervention needed)
5. 04:00 p.m. - 05:00 p.m.: 15 cars (No intervention needed)
6. 05:00 p.m. - 06:00 p.m.: 24 cars (Intervention needed)
7. 06:00 p.m. - 07:00 p.m.: 9 cars (No intervention needed)
8. 07:00 p.m. - 08:00 p.m.: 8 cars (No intervention needed)
9. 08:00 p.m. - 09:00 p.m.: 9 cars (No intervention needed)
After examining each hour, we can see that the traffic officer needs to intervene in hours 2, 4, and 6. Therefore, the correct answer is:
[tex]\[
\boxed{[2, 4, 6]}
\][/tex]
These are the hours during which traffic officer intervention is required.
