Solve the Problem $$\text { If } n ( A ) = 25 , n ( A \cup B ) = 73 \text {, and } n ( A \cap B ) = 21 \text {, find } n ( B ) \text {. }$$

Solve the problem.
- $$\text { If } n ( A ) = 25 , n ( A \cup B ) = 73 \text {, and } n ( A \cap B ) = 21 \text {, find } n ( B ) \text {. }$$

A) 69
B) 68
C) 48
D) 70