$1.$ Which of the following statements about interest rate swaps are correct?

i$.$ They are regarded as off$-$balance sheet financial instruments.

ii$.$ During the life of the swap, payments between the two parties are based on a notional principal amount.

iii. The periodic payments are executed in two different currencies.

iv$.$ The two parties exchange their individual debt obligations on reference dates.

$($a $)($i$)$ and $($ii$)$ only

$($b $)($iii$)$ and $($iv$)$ only

$($c $)($i$),($ii$)$ and $($iii$)$ only

$($d $)($i$),($iii$)$ and $($iv$)$ only

$($e $)$ None of the above