Let T(h)be the Temperature in Degrees Celsius at a Height

Let t(h) be the temperature in degrees Celsius at a height of h meters above the surface of the earth.What does t(h) + 15 mean in practical terms?

A) The temperature in degrees Celsius at a height h meters above the surface of the earth plus an additional 15 degrees
B) The height above the surface of the earth at which the temperature is h degrees Celsius plus an additional 15 meters.
C) The rate of change of temperature with respect to height at 15 additional meters above the surface of the earth (in degrees per meter) .
D) The rate of change of height with respect to temperature when the temperature is 15 additional degrees Celsius (in meters per degree) .