Multiple choice general knowledge math & puzzles

When you don't have it you want it, but when you do have it you want to share it , but you have to keep it. What is it?

  1. Favourite Item

  2. Friend

  3. A Secret

  4. Nothing

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

A secret fits the description: you want it when you don't have it, sharing it means it's no longer a secret, yet the riddle implies the act of sharing is the paradox of its existence.