Malik is singing at a concert for 80,000 people. Before the concert he ate a meal including chicken which was not cooked all the way. Malik is starting to feel nauseous (sick to his stomach). The feeling of nausea is an –

A. external stimulus because the crowd is super loud backstage.
B. external stimulus telling Malik to get rid of the food that he ate because it was not properly cooked.
C. internal stimulus telling Malik to get rid of the food that he ate because it was not properly cooked.
D. internal stimulus because the crowd is super loud backstage.