A.{a,b,c,d} B.{e,f} C.{b,a,c,d} D.{1,2,3,4. Set______and________ are not equivalent but are equal. The answer that I picked was B and D but I am not sure that it is those two.
From bob's definitions, confirmed by a Mathworld article below:
http://mathforum.org/library/drmath/view/65122.html
it is not possible to have two sets that are equal but not equivalent.