Question

A virtual image produced by a lens is always A. located in front of the lens. B. located in the back of the lens. C. smaller than the object. D. larger than the object.

Answer 1

I'd go for D on this one. The wording of B is odd, because it suggests to me that back surface of the lens - that is the surface of the lens that is remote from where the object is. 

Answer 2

A virtual image is usually located in back of the lens and is smaller than the object.

A few other things to know about virtual images:

virtual image - image that cannot be project on a screen because it is formed by rays that do not converge.

The images that are formed by concave lenses or mirrors are always: virtual, erect and diminished.

hope this helps :)