In an REF$615$ the low set stage for the line currents on the primary is set to $500$ A $($primary$.$If the line current is $2500$ A $($primary$),$ the line must be tripped in no more than $8$ sec$,$ but not faster than $4$ sec$.$ Use the long time inverse$-$time characteristic to determine the time multpilier$$for which the low set stage must be set and select one of the following options:

Group of answer choices

$1$

$0\mathrm{.}1$

$0\mathrm{.}5$

$0\mathrm{.}2$