Match each search method with branching factor b and search depth dwith its big$-$O bound

Group of answer choices

Breadth$-$first search

O$($b$^$d$)$ space

Depth$-$first search, generate all children at each node examined

$[$ Choose $]$

Depth$-$first search, generate children only as needed

O$($d$^$b$)$ space

Bidirectional search

O$($b$^($d$/2))$ space