What is the coding for the Date/Time group for the 9th of the month at 1755 UTC?

The correct coding for the Date/Time group is constructed according to specific formatting rules used in aviation weather observations, particularly METAR reports. The first two digits represent the day of the month, followed by the four-digit time in Coordinated Universal Time (UTC) expressed in a 24-hour format, and finally, a "Z" which designates that the time is in UTC.

For a date of the 9th of the month, the correct representation begins with "09." The time provided is 1755 UTC, which translates directly into the four-digit format as "1755." The inclusion of "Z" at the end indicates that this information is given in Zulu time (UTC). Thus, combining these elements together results in "091755Z," which accurately reflects the specified date and time.

In other options, variations such as using different letters such as "M" or "Y" are not standard for date/time notation in METAR reports. Additionally, an incorrect day configuration like "090755Z" does not correspond to the correct date of the 9th, and therefore doesn’t apply here.