Question

If j and k are parallel lines, A and B are points on j, and C and D are points on k, how many planes contain points A, B, C, and D?

A. Exactly one
B. None
C. We can't determine from the given information.
D. Infinitely many

Answer 1

A and B are points on j.

C and D are points on k.

Join AD and BC.

ABCD is a quadrilateral.

Clearly, the quadrilateral ABCD is the only plane that contains the points A, B, C and D.

Hence, correct answer is option A. Exactly one.