You will be given a definition of a task first, then some input of the task.
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'.

Question: Infections caused by Clostridium tetani, Bordetella pertussis, Corynebacterium diphtheriae and Vibrio cholerae have in common: 
 Options:  <1> The type of transmission. <2> The reservoir. <3> The production of exotoxins. <4> The affected organs. <5> The route of infection.
Output:
3