Leah Is Moving in a Spaceship at a Constant Velocity

Leah is moving in a spaceship at a constant velocity away from a group of stars. Which one of the following statements indicates a method by which she can determine her absolute velocity through space?

A) She can measure her increase in mass.
B) She can measure the contraction of her ship.
C) She can measure the vibration frequency of a quartz crystal.
D) She can measure the change in total energy of her ship.
E) She can perform no measurement to determine this quantity.