Answer the following question given this paragraph: 

At the top of the stratosphere is a thin layer called the stratopause. It acts as a boundary between the stratosphere and the mesosphere.


Q: What is the name of the thin layer that acts as a boundary between the stratosphere and the mesosphere?

 Choices:

- spirogyra

- ozone layer

- spicule

- stratopause

A:
stratopause
