What does fluency in reading signify?

Fluency in reading primarily signifies the ability to read a text accurately, quickly, and with appropriate expression. This skill allows readers to focus on the meaning of the text rather than the mechanics of reading, as fluent readers can recognize words and phrases effortlessly. Speed in reading refers to the rate at which a reader can go through the text, while expression indicates the reader's ability to convey emotions and understanding through their voice, appropriately emphasizing different parts of the text. This combination of elements is crucial for effective reading and comprehension, making option B the correct answer.

Understanding complex texts, having an extensive vocabulary, and comprehending literary devices are important components of reading and literacy, but they are not the primary indicators of fluency. Fluency is specifically about the smoothness and efficiency of reading itself rather than the depth of understanding or analysis of the text.