The correct option is D A∪C={a,p,l,e,k,w,i}
A is the set of letters of the word apple.
⇒A={a,p,l,e}
B is the set of letters of the word pineapple.
⇒B={p,i,n,a,l,e}
C is the set of letters of the word kiwi.
⇒C={k,w,i}
Now, A∪B={a,p,l,e}∪{p,i,n,a,l,e}
⇒A∪B={p,i,n,e,a,l}
Similarly, A∪C={a,p,l,e}∪{k,w,i}
⇒A∪C={a,p,l,e,k,w,i}