Consider the figure on the right side.

$($A$)$ The order of the nodes using prefix traversal is $x+-1238+42$

$($B$)$ The order of the nodes using infix traversal is

$(1-2+3)(8+42)$

$($C$)$ The tree is a binary tree.

$($D$)3$ and $8$ are internal node.

$($E$)-$ is an internal node.