Assume that the universal set is the set of integers. Let
AC={−3,−2,2,3},={x∈Z∣x≥−3},BD={x∈Z∣x2≤9},={1,2,3,4}
. In each of the following, fill in the blank with one or more of the symbols ⊂ , ⊆ , ⊆, = , =, ∈, or ∈/ so that the resulting statement is true. For each blank, include all symbols that result in a true statement. If none of these symbols makes a true statement, write nothing in the blank.
{3,2,1}_____D