∵当A⊊B时,满足A⊆B,
∴C UB⊊C UA,故A中C UA⊆C UB不成立;
C UA∩B≠φ,故D错误;
当A=B=U时,满足A⊆B,
C UA∪C UB=φ≠U,故B错误
而A∩C UB=φ恒成立,故C正确
故选C