Definition: In this task, you are given two facts, and a multiple-choice question. Based on the given facts, answer the question with index of the correct option (e.g, "A").
Input: Fact1: radioactive dating is used to determine the age of fossils, Fact2: Carbon 14 Dating Perhaps the best known radioactive dating is based on ., Question: The age of a fossil can sometimes be determined by what method? (A) microscope (B) an electron microscope (C) fossilized electrons (D) fossilized gamma rays (E) Carbon fibers (F) carbon 14 dating (G) chemical equations (H) Physical weathering
Output:
F