From the following table, identify isotopes and isobars.

Explanation

A and E are isotopes because they have same atomic number, i.e., X and mass numbers are different. Similarly, B and D are also isotopes. The mass numbers of A, C and D are X + Z + 2, X + 2 + 2 and X + Z + 2, respectively and their atomic numbers are X, X-2 and X + 1.
Therefore, they are isobars.
Similarly, B and E are also isobars.