设行列式D1=|a b c+a;a1 b1 c1+a1;a2 b2 c2+a2|,D2=|a b c;a1 b1 c1;a2 b2 c2|,则D1=( )

A.0 B.D 2 C .2D2 D.3D2
出自:信阳师范学院-代数选讲