A nucleus $_n^m{X}$ emits one α particle and two β– particles. The resulting nucleus is :

Question

( A ) $ _{n}^{m-4} {X}$
( B ) $ _{n-4}^{m-6} {Z}$
( C ) $ _{n-2}^{m-4} {Y}$
( D ) $ ^{m-6} _{n}{Z}$