What conclusions does Utterson reach based on Guest's observation?
a. Utterson concludes that Guest's observation confirms his suspicion about the sinister nature of Dr. Jekyll's relationship with Mr. Hyde.
b. Utterson concludes that Guest's observation is baseless and does not provide any conclusive evidence about Dr. Jekyll and Mr. Hyde.
c. Utterson concludes that Guest's observation raises questions about the true nature of Dr. Jekyll and Mr. Hyde's connection, but does not definitively prove anything.
d. Utterson concludes that Guest's observation is irrelevant to his investigation into Dr. Jekyll and Mr. Hyde.