Qualified plans must satisfy many tests to maintain qualified status. Which of the following is correct regarding coverage tests?

a. Defined benefit plans must pass any two of the four coverage tests.

b. Coverage testing includes employees covered under a collective bargaining agreement as part of the calculation.

c. Stock bonus plans must satisfy one of three coverage tests only.

d. Employees who do not meet the eligibility requirements are still included in the determination of at least one of the coverage tests.