5. The shape of iron plate A is an isosceles triangle, with its vertex angle being $45^{\circ}$ and the length of the legs being $12 \mathrm{~cm}$; the shape of iron plate B is a right trapezoid, with the lengths of the two bases being $4 \mathrm{~cm}$ and $10 \mathrm{~cm}$, and one interior angle being $60^{\circ}$. If they are arbitrarily flipped and tried to pass through a circular hole with a diameter of $8.5 \mathrm{~cm}$, the result is ( ).
(A) Plate A can pass through, Plate B cannot pass through
(B) Plate A cannot pass through, Plate B can pass through
(C) Both Plate A and Plate B can pass through
(D) Neither Plate A nor Plate B can pass through
5.A.

As shown in Figure 4, draw $B D \perp A C$ at point $D$, then
$$
B D=12 \sin 45^{\circ}=6 \sqrt{2}=\sqrt{72} \approx 8.5$, so the second board cannot pass through.