Question $5$

Consider a binary search tree with the keys $1,2,3,4,5.$ In what order can we insert these keys so that the height of the binary search tree is as small as possible with these keys? Choose all answers that apply.

$1.2,1,4,5,3$

$2.2,1,5,4,3$

$3.3,1,4,5,2$

$4.4,1,5,3,2$