this question is about abstract algebra math 702

question:

Consider the group G = D8 (the dihedral group with 8 elements) and a set A. If A has 2 elements show that there is a transitive action of G on A, but no faithful action.

If A has 3 elements show that there is neither a transitive nor a faithful action of G on A.

If A has 5 elements show that there is a faithful action of G on A but no transitive action.