Consider the following multi$-$threaded pseudocode to send messages to and receive messages from a

buffer with size $3($i$.$e$.,$ there are $3$ slots for messages in the buffer$).$ Note that the buffer functions are

not thread$-$safe.sem$\_$wait$($&channel$->$sem$1)$;data $=$ buffer$\_$remove$($channel$->$buffer$)$;sem$\_$post$($&channel$->$sem$1)$;$\}$

void send$\_$msg$($channel$\_$t$*$ channel, void$*$ data$)\{$

sem$\_$wait$($&channel$->$sem$1)$;

sem$\_$wait$($&channel$->$sem$3)$;

buffer$\_$add$($channel$->$buffer, data$)$;

sem$\_$post$($&channel$->$sem$1)$;

sem$\_$post$($&channel$->$sem$2)$;

$\}$How can you fix the bug$($s$)$ in this code? Select all of the changes that must be applied to make this code

work.

Swap lines $2$&$3$

Swap lines $5$&$6$

Swap lines $11$ & $12$

Swap lines $14$ & $15$

None of these $($i$.$e$.,$ no bugs$)$