The correct crontab entry to execute the script chklog three times per month between 3 p.m. and 5 p.m.:

This entry runs every minute (`*`) at 3 AM, 4 AM, 5 AM (`3,4,5`), which is the wrong time and too frequent for minutes.

This entry runs at minute 3 (`3`) at 3 AM, 4 AM, 5 AM (`3,4,5`), which is the wrong time.

This entry runs at minute 3 (`3`) at 3 PM, 4 PM, 5 PM (`15,16,17`) every day of every month (`* * *`), not just on the 1st of the month.

The crontab syntax is `minute hour day_of_month month day_of_week command`. This entry specifies `0` for the minute (on the hour), `15,16,17` for hours (3 PM, 4 PM, 5 PM in 24-hour format), `1` for the day of the month (the 1st), and `*` for month and day of week (every month, every day of week, effectively constrained by the day of month).

This entry runs every minute (`*`) at 3 PM, 4 PM, 5 PM (`15,16,17`), which is too frequent for minutes, even if the hours and day of month are correct.