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 upper rock layers are much younger.
 Question: Tom was digging in his backyard one day, after two inches he picked up an oval shaped rock. Tom kept digging and after twelve inches he picked up a square shaped rock, which rock was older? 
 Choices: A)The Oval Shaped Rock 
B)The Square Shaped Rock
The Square Shaped Rock