Assume the cost object is the company's various sales representatives. Furthermore, assume that the company spent $50,000 of its total fixed selling expense on advertising and the fixed portion of the company's sales representatives' compensation. a. When the company sells 20,000 units, what is the total direct selling expense that can be readily traced to individual sales representatives? b. When the company sells 20,000 units, what is the total indirect selling expense that cannot be readily traced to individual sales representatives?