2. On a straight line, four distinct points in sequence are $A, B, C, D$. The point that minimizes the sum of the distances to $A, B, C, D$
(A) can be a point on the line $A D$;
(B) is only point $B$ or $C$;
(C) is only the midpoint of segment $A D$;
(D) has infinitely many.


2. (D)

Solution: It is easy to prove: the sum of the distances from each point on line segment $BC$ to the four points $A, B, C, D$ is equal to $AD + BC$.
This is the minimum of the sum of the distances from any point on the plane to $A, B, C, D$.