In 1953, stanley miller

In 1953, scientist Stanley Miller performed an experiment that may explain what occurred on primitive Earth billions of years ago. He sent an electrical charge through a flask of a chemical solution of methane, ammonia, hydrogen and water. This created organic compounds including amino acids.

Making amino acids is tricky, even in the laboratory. We know amino acids exist in some kinds of meteorites and interplanetary dust particles. When they rain down on a planet's surface, they import the possible building blocks of life, not necessarily life itself. Scientists think that along the way, there must have been a crucial step that turned atoms into organisms, but they still don't know what it is.

answer; ///i believe the correct answer is (aids) acquired immune deficiency syndrome;

the correct answer is 4) heat and pressure

metamorphic rocks arise from transformation of existing rocks types, in a process called metamorphism. during metamorphism the original rock(prolith) change into metamorphic rock by heating (150-200c) and pressure of more than 1000 bar. the original rock can be sedimentary, igneous, or existing metamorphic rock.