[A]: Radioactive carbon `^(14)C` method is quite accurate for relatively recent fossils, not older than 40,000 years.
[R]: It was discovered by Libby.
A. If both A and R are true and R is the correct explanation of A
B. If both A and R are true but R is not the correct explanation of A
C. If A is true and R is false
D. If both A and R are false