A Meter Stick on a Spaceship Lies at a 45º

A meter stick on a spaceship lies at a 45º angle perpendicular to the motion of travel. When the ship is moving at 0.80 c, the length of the meter stick, relative to a stationary observer, is

A) 0.42 m.
B) 0.82 m.
C) 0.87 m.
D) 1.00 m.