If set AAA is a proper subset of BBB (A⊂BA \subset BA⊂B), which of the following is always true?
n(A)<n(B)n(A) < n(B)n(A)<n(B)
n(A)=n(B)n(A) = n(B)n(A)=n(B)
A∩B=∅A \cap B = \emptysetA∩B=∅
A∪B=AA \cup B = AA∪B=A