A communication system for binary$-$coded decimal $($BCD$)$ codes uses even parity for enor detection. Assume the sender wants to send the two numbers: $9$ and $7.$ Then, the sender transmits:

$($Note: In this communication system, the parity bit is padded$/$added for every transmitted BCD digit$)$

a$.{10010111}_{?}$

b$.{01001}_{0111}{?}_{?}$

c$.11001\mathrm{.}00111$

d$.{111001}_{0111}{?}_{?}$

e$.0100110111$