Marco believes that incest is morally wrong. According to Haidt and colleagues' concept of moral intuitionism, the primary reason for Marco's moral belief about incest is that
a. He has a principled, reasoned opposition to incest that he can easily explain.
b. He unconsciously finds incest appealing.
c. The idea of incest makes him feel negative emotions such as disgust or anger.
d. He is an only child.