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'.
Input: Question: Reactions that use copper (I) salts as reagents to replace the nitrogen in the diazonium salts are called reactions of:
Options: <1> Sandmeyer <2> Chichibabin <3> Peterson. <4> Gabriel. <5> Diels-Alder.
Output:
1