Final answer:
A 401(k) plan (c) generally attaches to a profit-sharing or stock bonus plan and allows employees to save for retirement with potential employer matching contributions.
Step-by-step explanation:
A 401(k) plan (c) generally attaches to a profit-sharing or stock bonus plan. It is a type of retirement savings plan that allows employees to contribute a portion of their salary into an investment account, where the funds can grow tax-free until withdrawal during retirement.
Employers may match employee contributions up to a certain percentage, providing additional funds for retirement. It is important to note that long-term part-time employees may no longer be eligible for a 401(k) plan (d).