Final answer:
Waiving U.S. citizenship is not allowed for sailors who wish to participate in the advancement-in-rate exam for the E-7 rate, which is the rank of Chief Petty Officer in the U.S. Navy.
Step-by-step explanation:
The question is asking which enlisted rank in the United States Navy is not allowed to waive U.S. citizenship for the purpose of participating in the advancement-in-rate examination. Advancement-in-rate exams are tests that sailors take to move to higher enlisted ranks within the U.S. Navy. According to U.S. Navy regulations, sailors at certain ranks must meet specific criteria, including citizenship requirements, to advance to the next higher rank.
Among the options provided, E-7, which represents the rank of Chief Petty Officer, requires sailors to be U.S. citizens to be eligible for advancement. Waiving citizenship is therefore not allowed for sailors participating in the advancement-in-rate exam for the E-7 rate.