The correct option is A Dialogues
Plato's writings mostly take the form of dialogues in which knowledge is revealed as two characters ask and answer questions of each other. Plato used this method in his book The Republic. He writes this book as if he is asking questions as a student and Socrates is answering as his teacher. Dialectics is a question and answer type of method where the student has a vague idea about something and throws questions to the teacher about it and the teachers answers are again questioned. By this the teacher facilitates the student to formulate and reformulate his idea in order to arrive at the best possible understanding of the idea.