x-rays infrared waves microwaves ultraviolet rays
I gave my students this multiple choice question: Visible light passes through glass. Other types of electromagnetic radiation are able to pass through other materials in a similar way. Which of the following are used in medical technology because they can pass through some parts of the human body?

Only one answer is correct among these 4 choices:
- x-rays
- infrared waves
- microwaves
- ultraviolet rays

Could you tell me which one is correct?

x-rays