The values of `d_(1)` & `d_(2)` for final rays to be parallel to the principal axis are: (focal lengths of the lenses are written above the respective lenses in the given figure)
A. `d_(1)=10 cm, d_(2)=15 cm`
B. `d_(1)=20 cm, d_(2) =15 cm`
C. `d_(1)=30 cm, d_(2)=15 cm
D. none of these