Of the following, which is most correct? a. In virtue ethics, it is important to define a moral virtue as both a habit and a mean. b. In virtue ethics, it is important to define a moral virtue as both a categorical imperative and a mean. c. In virtue ethics, it is important to define a moral virtue as both a gift from God and a subjective feeling. d. In virtue ethics, it is important to define a moral virtue as both a habit and a means to an end.