Answer: B
A = {2, 3, 5, 7}, B = {2, 5, 8, 9} then A U B = {2, 3, 5, 7, 8, 9}
let A be any set, then the set of all subsets of A is called power set of A and it is denoted by P(A) or 2^A.
If A= {1,2,3}, then P(A) = {ɸ, {1}, {2}, {3}, [1,2}, {2,3}, {1,3}, {1,2,3}}
If Cardinality of the power set of A is n, then |P(A)|= 2^n
|A U B| = 6
|P(A U B)| = 2^6 = 64