Given the task definition and input, reply with output. 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").

Fact1: Pressure receptors are found mainly in the skin., Fact2: Sensory Receptors A receptor is any structure specialized to detect a stimulus., Question: Something specialized to detect a stimulus is found mainly where? (A) fields (B) humans (C) bushes (D) bats (E) a path (F) skin (G) retina (H) Birds
F