Element a Exists in Three Isotopic Forms with Masses of 21.0

Multiple Choice

Element A exists in three isotopic forms with masses of 21.0, 25.0 and 26.0 amu, respectively. Element Q also exists in three isotopic forms with masses of 20, 24.0 and 25.0 amu, respectively. It is true that:

A) Element A has a lower atomic mass than element Q since it has the lightest isotope.
B) Elements A and Q have identical atomic masses since the sums of their isotopic masses are equal.
C) Element Q has a higher atomic mass than element A since its atomic masses are closer together.
D) More than one correct response.
E) No correct response.