(A) Carbenes act as free radicals.
(R) Only triplet carbenes act as biradical (divalent free radical).
A. If both (A) and (R) are correct and (R) is the correct explanation of (A).
B. If both (A) and (R) are correct but (R) is not the correct explanation of (A).
C. If (A) is correct but (R) is incorrect.
D. IF (A) is incorrect but (R) is correct.