The correct answer is A, they are friends, yet they have nothing in common. These two men are distant relatives who enjoy spending time with each other. They look forward to their long weekly strolls, in which they do not speak. In spite of not having much in common, they do have similar temperaments, a family trait. They both dislike gossip and prefer to contain their thoughts.
Besides, Utterson is the counterpoint to Hyde. They both have traits of coldness, although Utterson seems to also have "human" attitudes, not shown in his speech but in his actions. In addition, Hyde and Utterson like adventure, as opposed to Enfield, who is not inclined to it much.