Given the task definition and input, reply with output. You are given a science question (easy-level) and four answer options (associated with "A", "B", "C", "D"). Your task is to find the correct answer based on scientific facts, knowledge, and reasoning. Do not generate anything else apart from one of the following characters: 'A', 'B, 'C', 'D'. There is only one correct answer for each question.

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