A convex mirror has a focal length of 3 m. A 4 cm tall upright, real object is positioned 2 m in front of the mirror, along the principal axis. What is the image distance?
A. 0.83 meters in front of the mirror
B. 1.2 meters behind the mirror
C. 1.2 meters in front of the mirror
D. 0.83 meters behind the mirror