Which of the following is an accurate statement about qualified pension and profit sharing plans?

a. A plan that is or becomes top-heavy will cease to be qualified until certain corrections are made.

b. In a plan that is integrated with Social Security, the combination of the two benefits will produce a greater proportionate benefit for higher-paid employees than for lower-paid employees.

c. An employer can make contributions to a profit sharing plan in a year in which it has no profits.

d. The amount an employer may contribute to a qualified plan varies, depending on the number of employees and their years of service.