[单选题]
An object is placed 40 cm p bc3;fr:2zq qnoh /23gx uoa)iqkvko /mu;70 )o f/ptan front of a 20 cm focal length converging lens. How far is the imkouv ;/p7tm/k qa of)0age of this object from the lens?
A. $40 \; cm$
B. $20 \; cm$
C. $13 \; cm$
D. none of the given answers