Sentence fragments are incomplete sentences that make absolutely no sense, so I'm assuming that the best answer to this questions would be B avoided when writing.
In writing, sentence fragments are a set of words that act as a section or piece of a sentence but not as a complete sentence and therefore do not express a complete idea or thought. Due to this, including sentence fragments, while writing might confuse the reader or make the text difficult to understand or inconsistent. Therefore, in writing it is better to avoid using sentence fragments and instead only write complete sentences following the conventions of language and punctuation.
