3. As shown in Figure 1, given that $P A$ and $P B$ are tangents to $\odot O$, with $A$ and $B$ being the points of tangency, $C$ and $D$ are points on $A P$ and $B P$ respectively. Connect $O A$, $O B$, $O C$, $O D$, $O P$, and $C D$. Let the perimeter of $\triangle P C D$ be $c$. If $r=2 A P$, then the line $C D$ and $\odot O$ ( ).
(A) intersect
(B) are tangent
(C) are disjoint
(D) cannot be determined

保留了原文的换行和格式。
3. B.

As shown in Figure 6, draw $O F \perp C D$ at point $F$, extend $C A$ to point $E$ such that $A E=B D$, and connect $O E$.
Then $\triangle A O E \cong \triangle B O D \Rightarrow O E=O D$.
Let $c=2 A P$
$\Rightarrow C D=A C+B D=A C+A E=C E$
$\Rightarrow \triangle E O C \cong \triangle D O C$
$\Rightarrow O A=O F$
$\Rightarrow$ line $C D$ is tangent to $\odot O$.