(A) Any kind of exchange force helps the nucleus to be more destabilised.
(R ) `pi`-mesons are exchanged between nucleons incessantly.
A. If both (A) and (R ) are correct and (R ) is the correct explanation for (A).
B. If both (A) and (R ) are correct but (R ) is not the correct explanation for (A )
C. If both (A) and (R ) are incorrect.
D. If both (A) and (R ) are incorrect.