TASK DEFINITION: You are given a question or fill-in-the-blank question, two answer options (Option1 and Option2) and an Explanation. Your task is to find the correct answer (return the string of the correct option, not option1/2) for the given question from the given options and using explanation.
PROBLEM: Question: If Mona is excavating an archeological site and she discovers some fossils near the surface then compares them to fossils she found deeper down, which fossils will be younger? 
 Option1: near the surface 
 Option2: deeper down 
 Explanation: Lower rock layers were laid down earlier, so they are assumed to contain older fossils.

SOLUTION: near the surface

PROBLEM: Question: If Jim is screwing in two bolts and the first one has threads that are close together while the second one has threads that are far apart, which one must he apply less force to? 
 Option1: first bolt 
 Option2: second bolt 
 Explanation: The trade-off when the threads are closer together, is that more turns of the screw or bolt are needed to do the job because the distance over which the input force must be applied is greater.

SOLUTION: second bolt

PROBLEM: Question: Karen and Andie went to the beach together. Andie was trying to work on her tan so she used a sunscreen with a SPF 15, while Karen used a sunscreen with SPF 45, which Sunscreen protected the skin less? 
 Option1: Sunscreen SPF 15 
 Option2: Sunscreen SPF 45 
 Explanation: A sunscreen with a higher SPF protects the skin longer.

SOLUTION:
Sunscreen SPF 15