Although the earth's crust formed relatively early in the earth's history, it was not present when the earth first began to form. also, plate tectonics has recycled the earth's crust throughout most of its history.

using this information, what can be concluded about the age of the earth if the oldest known rocks in the earth's crust are 4.28 billion years old?

a. the earth is exactly 4.28 million years old.
b. the earth is younger than 4.28 billion years.
c. the earth is older than 4.28 billion years.