Which statement includes a rebuttal?
a. while twain's topics are often serious, he uses humorous techniques in his writing to make the topics less upsetting for his readers.
b. while some say that twain's use of sarcasm is inappropriate in serious situations, evidence shows that small amounts of humor people cope with serious topics.
c. twain's use of sarcasm makes his stories entertaining no matter what the topic.
d. twain's use of sarcasm and other humorous techniques shows that he doesn't take anything seriously and doesn't think his readers should either.