7) Please answer full question (a-c) for thumbs up.

Suppose you have a search problem in which actions can have a negative cost. Answer the following questions briefly but precisely:

a) What is the effect of arcs with negative costs on the behavior of uninformed search algorithms?

b) Does it make any difference if the search space is a tree or a graph?

c) Does it make any difference if you have ia lower bound for the negative costs (i.e. they are greater or equal to some negative constant)?