[单选题]
An object is 4.1 cm 3swz ,;2lbw wj f5qz ee0)pwn8: cd:mll8ejf3tall, and 10.3 cm from a converging lens. The image is virtual and 6.2 cm tallplf3cnqf:8eldw m 0)zej5 e:8. What is the focal length of the lens?
A. $6.8 \; cm$
B. $10 \; cm$
C. $16 \; cm$
D. $30 \; cm$
