Given the task definition and input, reply with output. You are given a short paragraph, a question and two choices to answer from. Choose the correct answer based on the paragraph and write the answer(not the key).

Paragraph: The main law is the law of superposition. This law states that deeper rock layers are older than layers closer to the surface.
 Question: If Jim is exploring layers of rock and he moves closer to the surface, what happens to the age of the rock? 
 Choices: A)older 
B)younger
younger