If a Laser Light Pulse Was Sent Toward the Moon

Multiple Choice

If a laser light pulse was sent toward the Moon and some of this light were to be reflected toward Earth from retroreflectors left on the Moon by astronauts, how long after the transmission of the initial flash would the reflected light be detected through a telescope on Earth?

A) 2.56 microseconds
B) 2.56 seconds
C) 1.28 seconds
D) 1.28 milliseconds