Multiple choice general knowledge

I am a box that holds keys without locks, yet they can unlock your soul. What am I?

  1. Lock

  2. Keyboard

  3. Mobile

  4. A piano

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A piano has musical keys but no locks. Music played on a piano can emotionally move people, metaphorically 'unlocking the soul.' This is a classic riddle playing on the double meaning of 'keys.'