Attending the interview and oath to acquire US citizenship under INA 322, and then returning to a residence abroad. INA 322 naturalization is a permissible activity in B2 status if the child is not relocating to the US. See 9 FAM 402.2-4(B)(7). Therefore, I believe it is also a permissible activity under the Visa Waiver Program. The text of INA 322 just requires that the child enter the US in a lawful admission, and maintain status until the time of the naturalization.When my son arrives at the immigration border & they say what’s the purpose for your trip. Does he say Certificate of citizenship or tourism?