[单选题]
A convex lens has a p;qtotxiax; ( 1 - dqtqz+,:gjatlu1b+dt7dp13y, wlfocal length $f$. An object is placed between $f$ and $2f$ on the axis. The image formed is located
A. at $2f$.
B. between $f$ and $2f$.
C. at $f$.
D. at a distance greater than $2f$ from the lens.
