Final answer:
Selling costs generally refer to expenses directly tied to the sales process, including sales commissions, sales salaries, and advertising, but not administrative salaries which are considered general expenses.
Step-by-step explanation:
Selling costs include expenses that are directly related to the selling of products or services. Specific types of selling costs include sales commissions, which are fees paid to salespeople as a percentage of the sales they generate, and sales salaries, which are fixed wages paid to sales staff. Additionally, advertising costs, which cover the expenses for marketing and promoting products or services, are considered part of selling costs. However, administrative salaries, which are related to clerical or office functions and are not directly tied to the sales process, are typically categorized as administrative or general expenses, not selling costs.