Which of the following corrects the pronoun error in this passage? The sixth-grade students liked volunteering their time to read to the elderly people in the hospital. It made them happy. The sixth-grade students liked volunteering his or her time to read to the elderly people in the hospital. It made them happy. The sixth-grade students liked volunteering their time to read to the elderly people in the hospital. It made the volunteers happy. The sixth-grade students liked volunteering their time to read to the elderly people in the hospital. They made them happy. The sixth-grade students liked volunteering their time to read to the elderly people in the hospital. Reading made them happy.