Please help with these questions

17, Let S be the set of the English Alphabet all in lower case letters, that is S (a,b,c,d,e,f,g,h,ij.k.,.., .x.yz, let A- (a,e,i,o,u and B-(Il.m,n,o.p.s.t.u.v. Are the set A, B subsets of S? Answer True of False: A True B. False 18. Let S, A, and B be the set defined as in question #17, Then what is AUB7 Chose your answer: A. AUB-(a,e,i.l,m,o B. AUB A C. AUB = {a,e,i,l,m,n,o,p,s,t,u,v) 19. S, A, B as defined in question #17, what is (AUB), Chose your answer: A. A, n B' B A'UB C. None of the above S A, Bare defined as in question #7 andC-{ p,q,r,s,t,u,v) what is AnBnc? Chose your answer 20. A. An B n C = C