Which of the Following Statements Best Describes the First Life-Forms

Which of the following statements best describes the first life-forms on Earth, which existed about 3.6 billion years ago?

A) Microbial life began at a time when the planet's atmosphere and climate were very different from today.
B) Microbial life began at the same time the Earth turned into a solid.
C) Microbial life evolved rapidly into more complex life forms in only a few hundred million years.
D) The first microbial life forms were restricted to what is now the Middle East.
E) Evidence for the first microbial life forms is found in igneous rocks.