Jireh flew his crop duster from the ground to an altitude of 3,500 feet. He continued to fly at that height for 20 minutes until he descended to 2,000 feet. He then flew back to the ground and landed his plane.

Which part of the scenario is best represented by a linear increasing interval?

Jireh flew his crop duster from the ground to an altitude of 3,500 feet.
Jireh flew at 3,500 feet for 20 minutes.
Jireh descended to 2,000 feet.
Jireh landed his plane.

Question

Jireh flew his crop duster from the ground to an altitude of 3,500 feet. He continued to fly at that height for 20 minutes until he descended to 2,000 feet. He then flew back to the ground and landed his plane. 

Which part of the scenario is best represented by a linear increasing interval?

 Jireh flew his crop duster from the ground to an altitude of 3,500 feet.
 Jireh flew at 3,500 feet for 20 minutes.
 Jireh descended to 2,000 feet.
 Jireh landed his plane.