Candice wants to increase her contribution to the maximum allowed under the Internal Revenue Code. The plan's current limitation on employee contributions is: 

a. Illegal as the only limitation on employee contributions may be imposed by the Internal Revenue Code or ERISA. 

b. Illegal as this limitation affects a non-highly compensated employee.

c. Legal provided 51% of the employees agreed in advance to the restriction. 

d. Legal without any approval by any third part