If you remove node $2,$ which of the other nodes in this binary search tree will replace it$?$

$6$

$/\backslash$

$28$

$/\backslash /$

$147$

$/\backslash$

$35$

Question $99$Select one:

a$.$

$3$

b$.$

$1$

c$.$

$5$

d$.$

$4$