(a) When an authorization is required by the Act, the monetary limitations and time requirements specified in G.S. 95-25.8 of the Wage and Hour Act apply and shall not be waived. (b) Deductions for the convenience of the employee, as that term is used in G.S. 95-25.8, include savings plans, credit union installments, savings bonds, union or club dues, uniform rental or cleaning not required by the employer, parking and charitable contributions. (c) A "reasonable opportunity to withdraw," as that