You are meeting to discuss the proper categorization of marketing strategy costs in the monthly department budget performance report. You are especially interested in making sure the fixed and variable costs are properly categorized. The major costs associated with the marketing strategy are as follows: Salesperson commissions Office space rent Office equipment rental Product raw materials Product manufacturing labor With respect to the variable or fixed nature of these costs, . a. we know that office space rent is a variable cost b. we know that product raw materials and office space rent are both fixed costs c. we know that office equipment rental, office space rent, and sales commissions are all fixed costs d. we know that salesperson commissions, product raw materials, and product manufacturing labor costs are all variable costs