Here's a problem to solve: 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?

Among the 4 following options, which is the correct answer?

- A: x-rays
 
- B: infrared waves
 
- C: microwaves
 
- D: ultraviolet rays
 