What are considered hidden sources of Social Security income?

The correct option identifies workers who have paid into the Social Security system through various employment avenues, including self-employment. These earnings contribute to an individual's Social Security record, and once a worker qualifies with sufficient work credits, they may be eligible for benefits like retirement, disability, or survivors' benefits. This source of income might not be immediately apparent as it does not involve direct payments until the worker reaches eligibility for benefits, making it a hidden source of Social Security income.

Other options do not align with the definition of hidden sources of Social Security income. Inheritances and gifts, investment income and dividends, and cash payments from family members are generally not classified as Social Security income since they are not derived from work that contributes to Social Security benefits. Such sources might be part of personal finances but do not interact with the Social Security system in a way that creates eligibility for benefits tied to one’s work history.