Final answer:
Sales commissions are the variable cost for an insurance company, as they fluctuate with the number of sales or policies sold, unlike rent, the president's salary, and property taxes, which are fixed costs.
Step-by-step explanation:
In the context of an insurance company, the variable cost is a type of expense that varies with the level of business activity. Among the options provided, sales commissions are a variable cost because they are directly tied to the number of sales or policies sold by agents.
Unlike fixed costs such as rent, the president's salary, and property taxes -- which remain constant regardless of the company's level of sales -- sales commissions fluctuate with the performance and sales volume.
The major additional costs to insurance companies, aside from payouts for claims, include managing business operations and covering administrative expenses like hiring staff and administrating accounts.
However, these costs must allow room for the firm's profits after paying for the average person's claims and the operational costs of running the company. Therefore, sales commissions are the variable costs that can change according to the number of policies sold.