Mr. Martinez is working with several middle school students who are reading at a​ second-grade or​ third-grade level. The students have shown little interest in reading materials that have been specifically designed to help them improve basic skills in phonics and reading comprehension.​ However, when Mr. Martinez instead gives them​ easy-to-read adventure and science fiction​ novels, they start reading regularly and even ask to take the books home so that they can continue reading after school. Is reinforcement occurring in this​ situation? Explain your decision.