Which statement is correct? (2 points) Select one:
a. Light can travel in a vacuum, and it travels faster if the light source is moving.
b. Light can travel in a vacuum, and its speed is constant if the source is moving or stationary.
c. Light can travel in a vacuum and will travel faster if the light source is moving.
d. Light can travel in a vacuum, and it travels more slowly if the light source is stationary.