Carter has recently become interested in the martial arts because of their self-defense benefits. he has written an essay to convince his friends and family members to join martial arts classes so that they will be more capable of self-defense. the opening sentence in his essay is martial arts classes will benefit almost anyone. which of these is a clear improvement of his opening sentence? a) learning martial arts is something that i believe everyone should do. b) people who take martial arts classes gain a lot of important knowledge. c) martial arts classes will teach everyone important skills that they can use. d) taking martial arts classes people gain important self-defense skills.