from The Strange Case of Dr. Jekyll and Mr. Hyde (1886) by Robert Louis Stevenson

MR. UTTERSON the lawyer was a man of a rugged countenance, that was never lighted by a smile; cold, scanty and embarrassed in discourse; backward in sentiment; lean, long, dusty, dreary, and yet somehow lovable.

The narrator calls the relationship between Mr. Utterson and Mr. Enfield "a nut to crack for many" because

A. they looked like two versions of the same man.

B. people did not see what they liked about each other.

C. neither man ever spoke to anyone.

D. people saw them arguing and bickering with each other constantly.