Answer:
The correct answer is the first one: Socrates taught by asking questions.
Explanation:
The third statement is wrong because it's Socrates the philosopher who left no writings. The second statement is not entirely correct: Socrates saw logic as a tool for ethics but it wasn't a central point in his thinking.
The first statement is correct. His method of dialectic inquiry is his most striking legacy. In this method, Socrates asked questions in order to check a problem from every possible point of view and used of irony to show a person that what he/she was certain about is actually wrong.
