Correct Answer: credulous

Solution : The correct choice is the first option.

Explanation:
A credulous person is someone who tends to believe things easily or without much evidence. They're often prone to accepting information without questioning its truth or reliability. Being credulous means being overly trusting or gullible, sometimes leading to believing even implausible or untrue things.

The meanings of the other options are as follows:

• A creditor is a person or entity to whom money is owed.
• Reliable means trustworthy or dependable.
• Plausible means seemingly reasonable or believable.

Therefore, the correct answer is credulous.