$1-[2\mathrm{.}5$ Marks$]$ Which of the following will be true if the instruction NVIC$\_$Enable$\_$IRQO $($line# $30)$ is removed? $($Select all applicable$)$

a$-$ Only the first interrupt will be executed and then the processor will operate infinitely in sleep mode;

b$-$ PORTD Interrupt will be active since it is configured in line $7$;

c$-$ No interrupt will occur, and the microcontroller will operate infinitely in sleep mode;

d$-$ None of the above

$2-[12\mathrm{.}5$ Marks$]$ Modify the above program in such a way that the variable "count" is incremented alternatively by $4$ and $6($e$.$g$.,$ increment by $4,$ then by $6,$ then by $4,$ and so on$...)$ each time a high to low transition occurs on PTD$6$ is done.

Provide your answer inside this box ONLY

void PORTD$\_$IRQHandler$($void$)\{$

$//$ clear pending interrupts

NVIC$\_$ClearPendingIRQ$($TIMO$\_$IRQn$)$;

if $(($PORTD$->$ISFR & MASK$($SW$\_$POS$)))\{$

$\}$

$//$ clear status flags

PORTD$->$ISFR $=0$xfffffff;; $//$clear interrupt flag register