A climber is on a hike. After 2 hours he is at an altitude of 400 feet. After 6 hours, he is at an altitude of 700 feet.

Which equation represent the situation?

A. y−700=200(x−6)
B. y−700=300(x−6)
C. y−6=75(x−700)
D. y−700=75(x−6)