Final answer:
Option (D), The uncommon method for calculating union dues is an Annual lump sum. Union dues are typically deducted as a percentage of salary, a flat monthly fee, or an hourly rate, which are methods that align with regular pay cycles and ensure consistent funding for union activities.
Step-by-step explanation:
The method of calculating union dues that is not common is D. Annual lump sum. It is more typical for union dues to be negotiated in collective agreements and calculated through either A. a percentage of salary, B. a flat monthly fee, or C. an hourly rate. These methods align better with the regular pay cycles of employees and ensure a steady stream of funding for the union's activities.
Union dues are essential for unions as they fund the activities and resources needed to represent and advocate for their members. The method of collection must be practical and sustainable, which is why annual lump sums are less common. Employers deduct dues to advance income tax, social security contributions, and insurance programs through withholding tax, PAYE or PAYG systems.