2. Proposition A: In $\triangle A B C$, $A B=A C, D$ is the midpoint of side $B C$, then $\angle A B C+\angle C A D=90^{\circ}$;

Proposition B: In Rt $\triangle A B C$, $A D$ is the median on side $B C$, then $\angle A B C+\angle C A D=90^{\circ}$. These two propositions ( ).
(A) A true, B false
(B) A false, B true
(C) A true, B true
(D) A false, B false
2. A.

It is easy to prove: Proposition A is true; for Proposition B, when $\angle ABC$ is a right angle, it is clearly not a true proposition.