Final answer:
A mixture of hydrogen, water, ammonia, and methane can produce amino acids when exposed to electrical discharge like lightning, as demonstrated by the Miller-Urey experiment. These amino acids are the building blocks of proteins.
Step-by-step explanation:
The question refers to an experiment which demonstrates the formation of simple organic molecules from a mixture of gases when exposed to an energy source similar to lightning or ultraviolet light. The Miller-Urey experiment of 1952 proved that a gaseous mixture of hydrogen, water, ammonia, and methane, when subjected to an electrical discharge, could lead to the production of amino acids. These amino acids are the building blocks of proteins, suggesting that under early Earth-like conditions, such molecules could have spontaneously formed, leading to the origin of complex biological molecules and eventually life. Therefore, the answer to the question is b) Proteins.