3. (2001 Hunan Province Competition Question) In the cube $A B C D-A_{1} B_{1} C_{1} D_{1}$, $E$ is the trisection point of $A_{1} A$, $F$ is the trisection point of $C_{1} C$, $A E=2 A_{1} E, C F=2 C_{1} F$. A section is made through $B$, $E$, and $F$ in the cube. Among the following projection diagrams of the section on the corresponding faces, which one is incorrect?
(A)
(B)
(C)
(D)
3. Choose D. Reason: First, the vertices of the orthogonal projection of the section of the cube should be on the edges of the projection plane. Among these four figures, only $D$ does not satisfy this. Further analysis shows that when the section is projected onto the plane $D_{1} D B B_{1}$, it should form a line segment. Therefore, choose $\mathrm{D}$