Jessie draws a ray diagram to show how an image of a candle is produced by a concave mirror when the candle is placed in front of the center of curvature. jessie thinks the image should be virtual and behind the mirror. which best describes jessie’s error? the object should be placed anywhere on the principal axis. the object should be at the center of the curvature. the object should be between the center and vertex. the object should be between the focal point and vertex.

There are two rules of reflection for the concave mirror:
1)Any incident ray traveling parallel to the principal axis on the way to the mirror will pass through the focal point upon reflection.
2)Any incident ray passing through the focal point on the way to the mirror will travel parallel to the principal axis upon reflection.
Also, keep in that for concave mirror center of curvature is 2f.
Using these two rules we can construct the image. 
You should always use these two "special" rays, I will mark then 1 and 2 on the picture.
From the picture, we can see that if you place the object between the focus and vertex you get the virtual image.
The answer is: object should be between the focal point and the vertex