Answer:
The correct answer is option B, that is, Edwin Hubble.
Step-by-step explanation:
Edwin Hubble who lived within 1889-1953 is an American astronomer, who completed his studies from the University of Chicago. He discovered that nebulae are the galaxies and postulated the Hubble's law on the basis of which the universe is expanding.
According to him, the galaxies are going away from each other, and also stated that the distance of a galaxy is equivalent to its recessional speed.