In the 1950's, Stanley Miller and Harold Urey conducted an experiment which demonstrated that several organic compounds could be formed spontaneously by simulating the conditions of Earth's early atmosphere. The spark discharge apparatus was used that held a mix of gases similar to those found in Earth's early atmosphere over a pool of water, representing Earth's early ocean. Electrodes delivered an electric current, simulating lightning, into the gas-filled chamber. After allowing the experiment to run for one week, they analyzed the contents of the liquid pool. They found that several organic amino acids had formed spontaneously from inorganic raw materials. These molecules collected together in the pool of water to form coacervates. The spark discharge apparatus did not show alcohols and aldehydes. Thus, option A is correct and other options are wrong.