Context: And ice flows through Dean 's veins as every muscle in his body locks , freezing him in place . Sam steps forward , a shadow taking on stark definition as he steps into the circle of light and Dean feels his stomach twist and roll unpleasantly . His brother 's face is blank marble , expressionless and unreadable . His clothes look lived in , creased and marked and , as he steps closer , there 's a sickly sweet aroma wrapped around him , pervasive and cloying that makes Dean 's eyes water .

Question: What may be the reason Dean 's stomach is twisting and rolling ?
Options:
0. Dean is trying to get away but is making his stomach swell and move .
1. He is seeing his sibling in a non - human form and it makes him sick .
2. Dean is emitting a strange smell and it is making Sam sick to his stomach
3. None of the above choices .
Answer: 1