Correct Answer: Atheist

Solution : The correct choice is the first option.

The one-word substitute for "a person who believes that God does not exist" is atheist . An atheist is someone who lacks belief in the existence of God or gods.
The meanings of the other options are as follows:

• Fanatic refers to a person with an extreme and unquestioning enthusiasm for a particular cause or belief.
• Epicurean means pertaining to the pursuit of pleasure, especially in terms of enjoying fine food and drink.
• Hedonistic means dedicated to the pursuit of pleasure, often to the neglect of other concerns.

Therefore, the correct answer is atheist.