The diagonals of a quadrilateral are congruent but do not bisect eac other. The quadrilateral is:
Iso trapezoid Parallelogram Rectangle Rhombus
But none of these are necessarily correct (kite, anyone?)
I'm a little behind the times getting back to this question because I have been away a lot lately.
For a change, I have no problem with the wording of this question. Since the 2nd condition, that the diags do not bis each other, does not hold for three of the four choices, they cannot possibly be the answer. Therefore, I believe that "is" rather than "could be" is the correct usage.
While we're on the issue of grammar, "none of these are" is incorrect because "none" is short for "not one"; it should read "none of these is". Similarly, saying things like "no problems arise" (and many similar expressions) should be "no problem arises".