Assertion (A) : Maximum covalency of carbon si foure .
Reason (R) : Carnon ahs no d-orbitals in its valence shell .
A. If both (A) and (R) are correct and (R) is correct explanation of (A)
B. If both (A) and (R) are correct and (R) is not correct explanation of (A)
C. If (A) is correct , but (R) is incorrect
D. If (A) is incorrect but (R) is correct .