If you are eligible for Post-9/11 GI Bill benefits and Montgomery GI BillActive Duty (MGIB-AD), what action must you take before receiving any Post-9/11 GI Bill benefits? a. You must make an irrevocable election in writing before receiving any Post-9/11 GI Bill benefits b.You do not have to complete any actions before receiving any Post-9/11 GI Bill benefits c. You must sign up on VA.gov and select an option before receiving any Post-9/11 GI Bill benefits