A person who knows everything is ________.

The correct answer is Option (4) → Omniscient

Omniscient means knowing everything. It comes from the Latin omni- (all) + scire (to know), as in science.
Example: No teacher is omniscient; everyone has something to learn.

Why the Other Options are Incorrect?

Option 1: Omnipotent — Incorrect. Omnipotent means all-powerful (omni- + potens, powerful).
Example: No ruler is omnipotent.

Option 2: Omnivorous — Incorrect. Omnivorous means eating both plants and animals (omni- + vorare, to eat).
Example: Bears are omnivorous animals.

Option 3: Omnipresent — Incorrect. Omnipresent means present everywhere at the same time.
Example: Mobile phones have become omnipresent.