For purposes of product costing, explain how would you allocate or apportion each of the following items of overhead: (a) Traveler’s salaries, commissions and expenses (b) After-sales services costs...

For purposes of product costing, explain how would you allocate or apportion each of the following items of overhead:

(a) Traveler’s salaries, commissions and expenses

(b) After-sales services costs

(c) Warehousing costs

(d) Market research costs