The correct option is
A guess
In this sentence we would be looking for a word which best expresses "Conjecture" from the given options
Conjecture means an opinion or conclusion formed on the basis of incomplete information.
If we look into the given options,
Guess means estimate or conclude (something) without sufficient information to be sure of being correct. It is the correct answer
Knowledge means facts, information, and skills acquired through experience or education; the theoretical or practical understanding of a subject
intuition means the ability to understand something instinctively, without the need for conscious reasoning
Experience means practical contact with and observation of facts or events
Option A is correct