The boiling point of water (measured in degrees), at altitude (measured in feet), is modeled by the function () = −0.0018 + 212. in terms of altitude and temperature, which statement describes the meaning of the slope?

a. the boiling point increases by 18 degrees as the altitude increases by 1,000 feet.
b. the boiling point increases by 1.8 degrees as the altitude increases by 1,000 feet.
c. the boiling point decreases by 18 degrees as the altitude increases by 1,000 feet.
d. the boiling point decreases by 1.8 degrees as the altitude increases by 1,000 feet.