Select the option that can be used as a one-word substitute for the given group of words.

One who knows all things

Omniscient

The word that can be used as a one-word substitute for "one who knows all things" is omniscient.

• Omniscient means having complete knowledge of everything.
• Omnipotent means having unlimited power.
• Oligarchy means a form of government in which power is held by a small group of people.
• Ostracise means to exclude someone from a group or society.

Omniscient is the most appropriate word for the given group of words because it specifically refers to someone who knows everything. It is derived from the Latin words omnis, meaning "all," and scire, meaning "to know."