Which of the following was a change made to transportation during the 1920s?

A. Airplanes were invented and used for the first time.

B. Railroads were introduced, making it easier to ship goods. ***

C. The first canals between waterways were built.

D. Installment plans offered by car manufactures made it easier to buy automobiles.

I think B but I could be wrong. If B is incorrect I'll go with A?

No -- not railroads -- they were developed and used extensively in the mid 1800s. When were airplanes invented? Were they used in World War I?

What does your text say?

Mrs. Sue this is what the text says...

Railroads, automobiles, and airplanes are all forms of transportation and technology that emerged or improved in the 1920s. Automobiles, such as the one pictured, were made by an assembly line, which is a series of stations of workers, machines, and equipment at which people and machines add to, or assemble, the parts of a product.
After assembly, the finished automobiles were then ready to be purchased. Automakers made it easier for people of a variety of incomes to purchase automobiles. They introduced the installment plan to their customers. An installment plan is a purchase plan that allows consumers to pay for an item by making regular payments over a period of time. As a result, many more people could own cars, and auto sales increased. But I still can't figure out the answer.Please help!

Thanks. Your answer is in the second paragraph.

So its D?

Yes. D is correct.

Thanks so much Ms. Sue :)

You're very welcome, Amber.