Answer the following question given this paragraph: 

Light microscopes continued to improve and are still used today. However, to see extremely small objects, a different type of microscope, such as an electron microscope, must be used.


Q: What type of microscope is used to see extremely small objects?

 Choices:

- optical microscope

- X-ray microscope

- ultrasonic microscope

- electron microscope

A:
electron microscope
