4. Given that $\triangle A B C$ and $\triangle A^{\prime} B^{\prime} C^{\prime}$ are both equilateral triangles, and the bases of the two triangles $B C=B^{\prime} C^{\prime}$, and $A B>A^{\prime} B^{\prime}$. The orthocenters of $\triangle A B C$ and $\triangle A^{\prime} B^{\prime} C^{\prime}$ are denoted as $H$ and $H^{\prime}$, respectively. Let $M=\triangle A B C$'s area $\times \triangle H B C$'s area, $N=\triangle A^{\prime} B^{\prime} C^{\prime}$'s area $\times$ $\triangle H^{\prime} B^{\prime} C^{\prime}$'s area. Then, ( ).
(A) $M>N$
(B) $M=N$
(C) $M<N$
(D) The size of $M, N$ cannot be determined
4. $\mathrm{B}$ (Hint ${ }_{2} M$
$$
\left.=N=\frac{1}{16} \cdot B C^{2} .\right)
$$