[单选题]
The images formed by cnubkd63u . y7foncave lenseccy9 z2lgk9x /7jf/uk3kt yi;s
A. are always real.
B. are always virtual.
C. could be real or virtual; it depends on whether the object distance is smaller or greater than the focal length.
D. could be real or virtual, but always real when the object is placed at the focal point.