American scientists Stanley Miller and Harold Urey used an apparatus similar to the one in the diagram to simulate how life could have formed on Earth. The apparatus contained hydrogen gas, water vapor, ammonia, and methane. These gases were subjected to a spark, to simulate lightning. The Miller-Urey experiment showed that, under certain conditions, organic compounds could form from inorganic molecules. How did this, as well as other scientists’ contributions help explain the origin of life on Earth? (SC.912.L.15.8) A. Scientists think that life could not have developed through natural chemical and physical processes. B. The experiment proved that methane and ammonia will always give rise to organic molecules in any circumstance. C. Scientists think it is possible that organic compounds formed from the inorganic compounds present on Earth billions of years ago. D. The experiment used the exact inorganic compounds present on Earth billions of years ago and left little doubt about the mechanism of early life.