The correct answer is A. to enhance the setting.
Charles Dickens's novel Hard Times is a satirical book aimed at criticizing the English society of the time (19th century Victorian England). With that in mind, Dickens came up with some rather creative names for his characters in order to portray everything wrong with the society he was surrounded with.
For example, Mr. Gradgrind (a play on the word grind) is a cold man who doesn't care much about anything else other than actual facts; Mrs. Sparsit (a play on the word sparse) is a poor widow; Mr. Sleary (a play on the word slur) is a man who speaks with a lisp.
As you can see, the names of these characters are used to reveal what they are like, to criticize the society they are in, but also to make fun of them; what they are NOT used for is enhancing the setting.