If a $_a^b X$ species emits firstly a positron, then two $\alpha$ and two $\beta$ and at last one $\alpha$ is also after intially it fainally convets into stable $_d^cY$ species so correct relation will be : -

Question

( A ) a = c – 6, d = b – 0
( B ) a = c – 8, d = b – 1
( C ) a = c – 4, a = b – 2
( D ) c = b – 12, d = a – 5