Fill in the blank given in the natural deduction proof below for the sequent $p(q^{{?}^{?}}$notr$),p|--$notr with the most

appropriate option.

$p(q^{{?}^{?}}$notr$)$

$(x)$

$p$

$($X$)$

$q^{{?}^{?}}$notr

$($Y$)1,2$

notr

$($Z$)$

$x=$ assumption, $Y=$longrightarrowe,$Z={?}^{{?}^{?}}{e}_2$

$x=$ premise, $Y=$longrightarrowe,$Z={?}^{{?}^{?}}{e}_2$

$x=$ premise, $Y=e,Z={?}^{{?}^{?}}{e}_1$

$x=$ premise, $Y={?}^{{?}^{?}}{e}_1,Z={?}^{{?}^{?}}{e}_1$