TOEFL Reading: ETS-TOEFL阅读机经 - UERB63Y7MT38UK30L$

Why does the author refer to "inflating a balloon with small coins attached to its surface?" A. To help explain how the universe can expand while the galaxies remain the same size B. To imply that the universe must eventually stop expanding C. To support the statement that most stars are found in disk-shaped galaxies D. To help explain how the universe began as a single point of dense matter