Final answer:
Belle Estaphan's primary plan is both Internet Services and Orion International.
Step-by-step explanation:
Belle Estaphan's primary plan is Both A and C, which means she is covered by both Internet Services and Orion International.
Since Belle retired from Internet Services, it is likely that she still has medical insurance from that company, making it her primary plan. However, since she is also covered by her husband Bernard's plan from Orion International, that plan can also be considered her primary plan. Therefore, her primary plan is both A (Internet Services) and C (Orion International).