Answer: A. A travel agent's main income is from commissions.
Step-by-step explanation:
Travel agents assist people in planning a trip. They offer advice on companies that can be traveled with such as airlines and luxury buses as well as where travelers can lodge and go on sight-seeing. They are helpful because they can help tailor a trip according to a person's budget.
These agents usually have arrangements with these companies and locations mentioned above such that when the traveler pays those companies, the travel agent gets some commission from that. This represents their main source of income.