2. In rectangle $A B C D$, $A B=6, A D=8, M$ is the midpoint of $A D$. Then the area of $\triangle A M C$ is ( ).
(A) 12
(B) 15
(C) 18
(D) 20
(E) 24
2. A.
$$
S_{\triangle A M C}=\frac{1}{2} \times \frac{1}{2} \times 8 \times 6=12 \text {. }
$$