n the diagram below, segment PB is a tangent. IF AC = 45 and PA = 4, find PB.

Given that segment PB is a tangent, you can identify that segment PC is secant.
You know that:
[tex]\begin{gathered} AC=45 \\ PA=4 \end{gathered}[/tex]According to the Intersecting Secant-Tangent Theorem:
[tex]Tangent=\sqrt{Secant\text{ }segment\cdot External\text{ }secant\text{ }segment}[/tex]In this case, you can identify that:
[tex]Secant\text{ }segment=PC=PA+AC=4+45=49[/tex][tex]External\text{ }secant\text{ }segment=PA=4[/tex]Therefore, you can determine that:
[tex]\begin{gathered} PB=\sqrt{49\cdot4} \\ PB=14 \end{gathered}[/tex]Hence, the answer is: Option b.