Laying off workers RM95 per unit Subcontracting cost RM70 per unit Regular production cost RM30 per unit Overtime cost RM55 per unit Calculate and recommend the suitable production plan for SEROJA Sdn. Bhd. based on the following production plan: a) Plan A - Produce at a constant rate of 1800 units per month by varying inventory or subcontracting only.(7 marks) b) Plan B - Match demand by hiring and laying off workers only.(8 marks) C) Plan C - Keep a stable workforce by maintaining a constant production rate equal to the average requirements. Allow varying inventory levels and overtime