单选题：In the eighteenth century, cities became larger and larger.

In the eighteenth century, cities became larger and larger. People moved from the countrysideand small towns to the cities because there was more work for them to do in the cities.
On Sundays and holidays, they liked to leave the cities and have a good time in the countryside.
But not every family had a horse or a wagon ( 马车). People needed a simpler means of transportation (交通工具). Inventors in many countries tried to solve this problem.
The first bicycle, which was very simple, appeared in 1790. People called it "the horse onwheel". Then in 1861, after many improvements being made, the bicycle became a practical means oftransportation.
People liked bikes because they weren't as expensive as horses and didn't need to be fed. Theycould go anywhere and were easy to ride.
Today bicycles are everywhere.
根据以上内容,回答题.
The first bicycle appeared in the __________century. A．seventeenth
B．eighteenth
C．nineteenth
D．sixteenth