Answer:
A. “Just hang it there,” she said, “and let me help you with your coat.”
Explanation:
The sentence that BEST creates a suspicious mood is option A.
This is because, from the words of the speaker, she seems to be hiding something and does not want the other person to discover so she offers to help with his coat to cover whatever she is hiding.
Suspicious mood occurs when the actions, thoughts or words of a person induces the feeling of suspicion.