Because the Early Earth Was a Large Sphere of Magma

Multiple Choice

Because the early Earth was a large sphere of magma, the earliest rocks that formed here were recycled into the mantle long ago.What is the age of the oldest radiometrically dated rocks discovered on the planet? (Or, what is the age of the oldest remaining rocks on Earth?)

A) 6,000 years old
B) 4.6 million years old
C) 4 billion years old
D) 4.6 billion years old