Answer:
D. 4.5 billion years
Explanation:
Scientists study meteorites to determine the age of our solar system, since they are the oldest accessible material out there. Earth itself has rocks that are over 4 billion years old.
In recent times, meteorites have informed our view of, and our priorities about, what spacecraft – and perhaps, one day, human explorers – might find on Mars and other planets. And we now recognize that a cosmic delivery of life with an independent origin from our own would revolutionize our ideas about the extent of life throughout the whole known Universe.
