The protein$($s$)$ that appear$($s$)$ to be post$-$translationally modified by N$-$glycosylation is $($are$)$

X$3$ and X$4$

$"$X$1,$ X$3,$ and X$4"$

$"$X$1,$ X$2,$ X$3,$ and X$4"$

$x1$ and $x4$

X $1$ and X $3$

X$3$

X $1$