When an Object Moves Close to the Speed of Light

Multiple Choice

When an object moves close to the speed of light relative to Earth,what happens to its dimensions compared to what they were before it began moving,as measured by an Earth-based observer?

A) Only lengths parallel to the direction of travel are decreased.
B) Only lengths perpendicular to the direction of travel are decreased.
C) All lengths are decreased.
D) No lengths are affected.