If we used an inadmissible heuristic in A* tree search, could it change the completeness of the search?

No

Explanation:

If we used an inadmissible heuristic in A* tree search, it cannot  change the completeness of the search, and this is because as long as a heuristic function is bounded, then A* tree search would visit all the nodes available  and would definitely find a path to an existing goal

A* tree search is a  search strategy that is used to find and establish an efficient path between points, and the node in a search tree can be visited several times  as well

b.. i believe would be the right one sorry if im wrong.

ipr and related laws.