In the diagram below, two of the three rays used to find the image position are shown. which of the following best describes the third (missing) ray?

Option C

Explanation:

To find the position of the image when an object lies in front of lens, usually three rays are used. One incident ray passes through the focus and would be parallel to the axis after refraction from the lens. Second would just pass through the optical center. Third incident ray would be parallel to the axis and would refract from the lens and pass through the focus on the right hand side.  The three rays would be extended in both the directions and we would see where the three rays would intersect. That would be the position of the image.

Thus, the correct option is C.