4. In $\triangle A B C$, it is known that $M$ is the midpoint of $A B$, $N$ is a point on side $B C$, and $C N=2 B N$. Connecting $A N$ and $M C$ intersects at point $O$. The area of quadrilateral $B M O N$ is 14. Then the area of $\triangle A B C$ is ( ).
(A) 56
(B) 60
(C) 64
(D) 68
4. B.

As shown in Figure 1, connect $B O$.
Let $S_{\triangle BMO}=x$,
$$
S_{\triangle BNO}=y \text{. }
$$
$$
\text{Then } S_{\triangle MO}=x \text{, }
$$
$$
\begin{array}{l}
S_{\triangle CNO}=2 y, \\
S_{\triangle ACO}=3 y . \\
\text{Therefore, } \frac{2 x}{y}=\frac{S_{\triangle ABO}}{S_{\triangle BON}}=\frac{AO}{ON}=\frac{S_{\triangle AOC}}{S_{\triangle NOC}}=\frac{3 y}{2 y}=\frac{3}{2} \\
\Rightarrow x=\frac{3 y}{4} \Rightarrow x+y=\frac{7 y}{4}=14 \\
\Rightarrow y=8, x=6 \\
\Rightarrow S_{\triangle ABC}=2 x+6 y=60 .
\end{array}
$$