Answer:
a) {q, s, w, y}
Step-by-step explanation:
B ∪ C = {q, s, y, z} ∪ {v, w, x, y, z} = {q, s, v, w, x, y, z} . . . . elements in either set
A ∩ (B ∪ C) = {q, s, u, w, y} ∩ {q, s, v, w, x, y, z} = {q, s, w, y} . . . . elements in both sets (matches selection A)