3. The coefficient of $a b c^{2}$ in the expansion of $(a+2 b-3 c)^{4}$ is ( ).
(A) 208
(B) 216
(C) 217
(D) 218
3. B.

According to the problem, the coefficient of $a b c^{2}$ is $C_{4}^{2}(-3)^{2} C_{2}^{1} \times 2 \times 1=216$