He lives near a lonely . . . . . . . . of countryside.

The correct answer is: C. stretch

A stretch of countryside is a long, continuous area of countryside. It is often used to describe an area that is remote and sparsely populated.

The other options are:

• A. piece – a small part of something.
• B. length – the distance from one end of something to the other.
• D. section – a part of something that is separated from the rest.

In the context of the sentence, “He lives near a lonely stretch of countryside,” the word “stretch” is the most appropriate word to use. This is because it conveys the sense of a long, continuous area of countryside that is remote and sparsely populated.