Average roller coaster sizes are divided into the following categories:
Hypercoaster: more than 200 feet, that is, more than 61 m.
Gigacoaster: more than 300 feet, that is more than 91.5 m.
Stratacoaster: more than 400 feet, that is more than 122 m.
So an estimated measurement for an extreme roller coaster would be the answer C) 300ft