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: When the electromagnetic radiation passes from the air to a medium like glass its wavelength:
Options: <1> It remains unchanged. <2> Increase approximately 10 nm. <3> Increase approximately 100 nm. <4> It decreases approximately 1 nm. <5> It decreases approximately 200 nm.
Output:
5