describe explicitly in english the following sets, then give their cardinality. (a) {x ∈ 2z : 5 ∈ x} (b) {x ∈ 2z : x ⊆ {1, 2, 3}} (c) {x ∈ 2z : x ⊆ {1, 2, {3, 4}}} (d) {x ∈ 2z : x ∈ {1, 2, {3, 4}}}