We know that the complement of set A is A' = U - A
Given U = {a, b, c, d, e, f, g, h}
(i) A = {a, b, c}
A' = {d, e, f, g, h}
(ii) B = {d, e, f, g}
∴ B' = {a, b, c, h}
(iii) C = {a, c, e, g}
∴ C' = {b, d, f, h}
(iv) D = {f, g, h, a}
∴ D' = {b, c, d, e}