Question: A student made observations of four rock samples. Which of these observations most likely describes a sedimentary rock?

  Options: 
 A. Sample 1 has bands of light and dark crystals.
 B. Sample 2 has pink, gray, and white crystals grown together.
 C. Sample 3 is made up of one huge, pale pink crystal.
 D. Sample 4 is made up of layers of sand grains cemented together.
Answer: D