:) you

what is the connotation of the word uncommon in the context of these sentences from the count of monte cristo?

dantès in his cell heard the noise of preparation,—sounds that at the depth where he lay would have been inaudible to any but the ear of a prisoner, who could hear the splash of the drop of water that every hour fell from the roof of his dungeon. he guessed something uncommon was passing among the living; but he had so long ceased to have any intercourse with the world, that he looked upon himself as dead.

a. in short supply
b. remarkable
c. out of the ordinary
d. strange