Question #N1432

The ancient Greeks viewed the Pleiades, a cluster of stars, as a group of seven stars. They believed that these stars were the Seven Sisters, a group of women who had been transformed into stars. This idea is still popular in some cultures, though astronomers know that there are, in fact, only six visible stars in the cluster. The two stars that appear closest to each other are so close together that they appear to be a single star.

Which choice best combines the sentences in the underlined portion of the passage?
A. The two stars that appear closest to each other are so close together that they appear to be a single star, though astronomers know that there are, in fact, only six visible stars in the cluster.
B. Though astronomers know that there are, in fact, only six visible stars in the cluster, the two stars that appear closest to each other are so close together that they appear to be a single star.
C. The two stars that appear closest to each other are so close together that they appear to be a single star, and astronomers know that there are, in fact, only six visible stars in the cluster.
D. Astronomers know that there are, in fact, only six visible stars in the cluster; the two stars that appear closest to each other are so close together that they appear to be a single star.