Explanation:

- The Mesosphere is where most meteorites burn up upon entry due to increased air resistance and the presence of gases that cause friction.

- The Exosphere is the outermost layer of the atmosphere where there's very thin air. It doesn't have enough particles to cause meteorites to burn up.

- The Thermosphere is above the mesosphere and contains very thin air. While it heats up due to solar activity, most meteorites don't encounter significant burn up here.

- The Stratosphere is the second layer from the Earth's surface. It's largely stable and doesn't play a role in causing meteorites to burn up.

Mesosphere is the correct layer where meteorites burn up.