It is a rational statement
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.
One of the most common forms of weathering in areas that have frequent freeze/thaw cycles is ice wedging.