A certain light source sends out 2 x 10 15 pulses each second. As a spaceship travels parallel to the Earth's surface with a speed of 0.90c, it uses this source to send pulses to the Earth. The pulses are sent perpendicular to the path of the ship. How many pulses are recorded on Earth each second?

A- 4.6 x 1015 pulses/s

B- 3.8 x 1014 pulses/s

C- 6.3 x 1015 pulses/s

D- 8.7 x 1014 pulses/s