You are presented with the quiz "How does a guitar create sound?" But you don't know the answer, so you turn to your teacher to ask for hints. He says that "plucking a string can cause that string to vibrate" and "all guitars produce sound through the mechanical vibration of strings". So, what's the best answer to the question?

Available options: 1. electrically 2. mechanical 3. Amplifying it with electricity 4. The musician being trained 5. Tuning it properly 6. Plucking a string 7. Through play 8. lowered energy cost
Answer:
6.