A car is fitted with a convex side-view mirror of focal length 20 cm. A second car 2.8 m behind the first car is overtaking the first car at relative speed of 15 m/s. The speed of the image of the second car as seen in the mirror of the first one is :

Question

( A ) $10$ m/s
( B ) $15$ m/s
( C ) $\frac{1}{15}$ m/s
( D ) $\frac{1}{10}$ m/s