What is the English Channel?

a. an extension of the Atlantic Ocean between England and France

b. a landmass that connects Ireland to the United Kingdom

c. a long, narrow ocean inlet that passes between high and rocky banks or steep cliffs

d. a waterway that connects the Pacific and Atlantic Oceans

The English Channel is the body of water between England (Great Britain) and France, it is connected to the Atlantic Ocean.

Being a body of water, it can't be a water way - so the answer b) is false.

In fact, from the description above you know that the answer a. an extension of the Atlantic Ocean between England and France is true.