Answer:
C. An ellipse
Step-by-step explanation:
If you cut a cone on the side with an angle that will produce an ellipse-shaped plane.
if you were to cut the cone perpendicularly to its height (as if the double cone on the picture was straight up), you would get a circle as the plane, because it would be a transversal cut of a circular cone.
If you cut it with an angle, you're stretching the circle... so you'll have an ellipse.
It is NOT a parabola NOR a hyperbola, since both would require the cross-section to go through the base... which it does not in this problem. Please refer to the image below.
