Q: You are presented with the quiz "What can lasers be used for?" But you don't know the answer, so you turn to your teacher to ask for hints. He says that "alaser is used for producing light" and "lights illuminate the blackness". So, what's the best answer to the question?

Available choices: i. tag; ii. energy; iii. electricity; iv. illumination; v. focusing a lens; vi. space; vii. Destroy bridges; viii. air;
The answer is:
iv.