When Flying on a Plane,traveling at 500 Miles Per Hour,why

When flying on a plane,traveling at 500 miles per hour,why does your vestibular system not register the extremely fast linear motion?

A) Since you are inside the plane,the fast motion of the plane does not translate to your inner ear.
B) Since you are moving at a constant rate of speed,the fluid in your inner ear isn't moving and bending the stereocilia.
C) Since you are in a pressurized cabin,the speed of the plane doesn't affect the semicircular canals,only the pressure in the inner ear.
D) Your hair cells adapt to the constant fluid movement inside the semicircular canals and cease sending action potentials.