Detailed Instructions: In this task, you are given a multiple-choice question about healthcare. Answer the question based on your information and classify your answers into '1', '2', '3', and '4'.
Q: Question: Regarding the Gastrointestinal Stromal Tumors (GIST), it is true that:
Options: <1> These are tumors of epithelial origin, located mainly at the level of the mucosa of the digestive tract. <2> The mutation of the c-kit gene, which codes for a tyrosine kinase receptor, is characteristic of these tumors. <3> The treatment of localized tumors smaller than 2 cm is fundamentally medical, with the use of Imatinib. <4> They are tumors that only exceptionally bleed. <5> The most frequent localization of these tumors is the small intestine.
A:
2