Final answer:
c) A handwriting expert. A handwriting expert is able to analyze the handwriting on the letter Hyde sent to Jekyll.
Step-by-step explanation:
The handwriting on the letter Hyde sent to Jekyll can be analyzed by a handwriting expert. They have the knowledge and skills to examine the letter and determine the characteristics and style of the handwriting. By comparing the handwriting on the letter to known samples, they can identify the author of the letter.
In the given information, Jane Withersteen received a letter which was not in Bishop Dyer's own handwriting. This indicates that the letter was written by someone else, most likely by Mr. Hyde. Therefore, both Dr. Jekyll and Mr. Hyde would not be able to analyze the handwriting, as they are involved in the situation.
Based on the information provided, the handwriting expert would be the most suitable person to analyze the handwriting on the letter sent by Hyde to Jekyll.