The Inquiry would detect that the minimum age for the applicant to enter a specific grade will not be met by a certain date, so terminates the inquiry and requests that the prospective applicant wait a year because they are too young, or that they give the admission department a call.
It would benefit the admission department ,in that resources such as application packets and materials would not be sent to parents and guardians of students too young. We send them different marketing materials, and have a completely different tour later in the year.