26. In obtuse triangle $\mathrm{ABC}$, $\mathrm{AM}=\mathrm{MB}$, $\mathrm{MD} \perp \mathrm{BC}$, $\mathrm{EC} \perp \mathrm{BC}$. If the area of $\triangle \mathrm{ABC}$ is 24, then the area of $\triangle B E D$ is
(A) 9, (B) 12;
(C) 15;
(D) 18; 
(E) Not uniquely determined.
B
26. Connect $CM$, using the equal areas of $\triangle AMC$ and $\triangle BMC$ we get the area of $\triangle BMC$ is 12. Then, using the equal areas of $\triangle DME$ and $\triangle DMC$ we get the area of $\triangle SED$ is 12, i.e., (B).