Given below are two statements : one is labelled as Assertion \((A)\) and the other is labelled as Reason \((R)\). Assertion \((A):\) Polymerase chain reaction is used in DNA amplification Reason \((R):\) The ampicillin resistant gene is used as a selectable marker to check transformation In the light of the above statements, choose the correct answer from the options given below :

1. A Both \((A)\) and \((R)\) are correct but \((R)\) is not the correct explanation of \((A)\)
2. B \((A)\) is correct but \((R)\) is not correct
3. C \((A)\) is not correct but \((R)\) is correct
4. D Both \((A)\) and \((R)\) are correct and \((R)\) is the correct explanation of \((A)\)