Four points are always coplanar if they: check all that apply. a. lie on the same line. b. lie on different planes. c. lie on different lines. d. lie in the same plane.

D. lie in the same plane.

The definition of capillarity is that points are considered as co-planar when these points are on the same plane, so it is obvious that the answer D is true because this statement is the definition of capillarity. This is shown in Figure 1.

A. lie on the same line.

If four points lie on the same line then there will be a plane that contains this line, therefore the definition is fulfilled. This is shown in Figure 2.

Finally, the correct answers are A. and D.