(1) Researchers learned something interesting from studying the classrooms where students were offered some freedom of choice. (2) Students who were given choices were star performers. (3) The children who were able to choose what to read themselves were more successful at developing lasting literacy skills. (4) Being able to combine personal interests with schoolwork helped them to develop and enjoy a lifetime habit of learning. Where does it make the most sense to insert the transition “specifically”?

at the beginning of the first sentence
at the beginning of the second sentence
at the beginning of the third sentence
at the end of the paragraph