Subset Counting with Set-Theoretic Conditions

The question asks to count subsets, ordered pairs of subsets, or relations satisfying set-theoretic conditions such as disjointness, union, intersection, or element-overlap requirements.

turkey-yks 2019 Q18 View
Let A and B be non-empty sets consisting of digits. If
$$A \cap B = A \cap \{ 0,2,4,6,8 \}$$
equality is satisfied, then A is called the common-intersection set of B. Given that set A is the common-intersection set of
$$B = \{ 0,1,2,3,4 \}$$
how many different sets A are there?
A) 3
B) 7
C) 15
D) 31
E) 63