How frequently can an individual change their health plan in the Marketplace?

The correct answer is C, as individuals can change their health plan in the Marketplace during open enrollment periods or when they qualify for a special enrollment period. Open enrollment typically occurs once a year, allowing individuals to enroll in, switch, or make changes to their existing health plans.

Special enrollment periods come into play when certain qualifying life events occur, such as getting married, having a baby, or losing other health coverage. These events allow individuals to change their health plans outside of the regular open enrollment period, ensuring that they can access necessary health coverage in response to life changes.

The other options do not accurately reflect the rules governing plan changes in the Marketplace. Changing plans once a year during tax season or only when moving to a new state does not align with the established guidelines. Additionally, saying individuals can change their plans anytime is misleading since it does not account for the structure provided by the open enrollment and special enrollment periods.