$($C$++)$ Which of the following statements is true about deleting the root of a

binary search tree?

e$.$ none of $($a$),($b$),$ and $($c$)$

c$.$ if the root has two children, its item is replaced by the largest ele$$ment in the right subtree

d$.$ all of the above

b$.$ the root changes if it does not have two children

a$.$ the root always changes