Answer :
In Stanley Miller and Harold Urey’s experiment, several D) Amino acids , which are the building blocks of proteins, began to accumulate.
Answer: Amino Acids
Explanation: Miller and Urey's experiment proved that life evolved from non living components. This experiment created the condition that was thought to be present at the time when early earth was formed.
This experiment was conducted in the 1952 when the scientist created the condition using water, thunderstorm( artificially in lab) and some more substances, which lead to the synthesis of life supporting substances such as amino acids. There were approximately 20 amino acids produced during this experiment.
