2 If each face of the tetrahedron is not an isosceles triangle, then the minimum number of edges with unequal lengths is ( )
A. 3
B. 4
C. 5
D. 6
2 A. The three edges of the same face are unequal. On the other hand, for a rectangular cuboid with length, width, and height all unequal, the tetrahedron formed by the face diagonals fits A.