[单选题]
An object is 4.1 cm tall, and 1/rbhqr6*5qr7vd* 50teeey. n urma)r0.3 cm from a convergns0/o0md 5niz-.m x,fkeuc7o4b,ft k ing lens. The image is virtual and 6.2 cm tall. f-fmiz/50 d ukm0e,nn7,.kob csx4otWhat is the focal length of the lens?
A. $6.8 \; cm$
B. $10 \; cm$
C. $16 \; cm$
D. $30 \; cm$