An astronomical telescope has an angular magnification of magnitude 5 for distant object. The separation between the objective and the eyepiece is 36 cm and the final image is formed at infinity. The focal length `f_(0)` of the objective and the focal length `f_(0)` of the eyepiece are
A. `45cm` and `-9cm` respectively
B. `50cm` and `10cm` respectively
C. `7.2cm` and `5cm` respectively
D. `30cm` and `16cm` respectively
