Answer:
B. A comparison of hotel costs and educational opportunities.
Step-by-step explanation:
This would be the best argument that the speaker could find in order to convince her class of going to Washington, D.C. instead of New York City. This is because these factors are more likely to be considered relevant by her class. Educational opportunities are very important if the class is organized by the school. Moreover, a comparison of hotel costs will ensure that the trip is affordable for most people.