We received 4 years before PR on employment based. We are planning to apply us citizenship for me and my husband and my son he is going to be 21 in 2 months. Will he eligible to apply us citizenship petition, if not what's the process, either of the parents should maintain GC status...please help ushttps://www.uscis.gov/green-card/green-card-processes-and-procedures/visa-availability-priority-dates/when-to-file-your-adjustment-of-status-application-for-family-sponsored-or-employment-based-56