number of electrons increases while that of electrons decreases

number of holes increases while that of electrons decreases

number of holes and electrons do not change

number of holes and electrons increases equally

$$ \begin{array}{|l|l|l|} \hline \text { A } & \text { B } & \text { Y } \\ \hline 0 & 0 & 0 \\ \hline 1 & 0 & 0 \\ \hline 0 & 1 & 0 \\ \hline 1 & 1 & 0 \\ \hline \end{array} $$

$$ \begin{array}{|l|l|l|} \hline \text { A } & \text { B } & \text { Y } \\ \hline 0 & 0 & 1 \\ \hline 1 & 0 & 0 \\ \hline 0 & 1 & 0 \\ \hline 1 & 1 & 1 \\ \hline \end{array} $$

$$ \begin{array}{|c|c|c|} \hline A & B & Y \\ \hline 0 & 0 & 0 \\ \hline 1 & 0 & 1 \\ \hline 0 & 1 & 1 \\ \hline 1 & 1 & 1 \\ \hline \end{array} $$

$$ \begin{array}{|l|l|l|} \hline \mathbf{A} & \mathbf{B} & \mathbf{Y} \\ \hline 0 & 0 & 1 \\ \hline 1 & 0 & 1 \\ \hline 0 & 1 & 1 \\ \hline 1 & 1 & 1 \\ \hline \end{array} $$

(i), (ii)

(ii), (iii)

(ii), (iii), (iv)

(i), (ii), (iii), (iv)