What Is the Significance of the Tunguska River Valley in Siberia

What is the significance of the Tunguska River Valley in Siberia in terms of asteroids?

A) It is where the largest comet was sighted.
B) It is where a large airburst of an asteroid occurred in recent history.
C) It is the site of a crater that marks the asteroid that killed the dinosaurs.
D) It is the site of the largest impact crater ever recorded on Earth.
E) It is a site of enormous wildfires in prehistoric times.