This element is commonly found, along with nitrogen and potassium, in fertilizers, and is characterized, along with nitrogen, arsenic, antimony, and bismuth, as a nictogen. This element exists in two forms, red and white, but due to its high reactivity, is never found as a free element on Earth. This element is essential to human life, and is often found in the remains of ancient fossils. For 10 points, name this chemical element, used in detergents, pesticides and fertilizers, and has an atomic number of 15 and chemical symbol P.
A) Phosphorus
B) Potassium
C) Nitrogen
D) Sulfur