A selection about Sally Ride in a 5th-grade textbook represents which genre?

The selection about Sally Ride in a 5th-grade textbook is correctly identified as a biography because it focuses on the life, achievements, and contributions of a specific individual. Biographies provide factual accounts of a person's life, detailing their experiences, struggles, and successes. In this case, the text likely covers important milestones in Sally Ride's life, such as her journey to becoming the first American woman in space, her educational background, and her impact on science and education.

While expository texts also aim to inform and educate, they typically cover broader topics or concepts rather than focusing on individual lives. Fiction implies that the content is imaginative and created from the author's mind, which does not apply to a factual recount of a person's life. A historical account may touch on events in the past but isn’t solely centered around an individual's personal story. Thus, the biographical nature of the selection makes it the most fitting genre.