Astronomers observe two galaxies, A and B. Galaxy A has a recession velocity of 2,500 km/s, while Galaxy B has a recession velocity of 5,000 km/s. This means that
a) galaxy A is four times as far away as galaxy G
b) galaxy A is twice as far away as galaxy B
c) galaxy B is twice as far away as galaxy A
d) galaxy B is four times as far away as galaxy A.
Answer: C