A compound microscope has the objective and eyepiece mounted in a tube that is $L=20\mathrm{.}0cm$ long. The focal length of the eyepiece is $2\mathrm{.}32$ cm $,$ and the near$-$point distance of the person using the microscope is $25\mathrm{.}0$ cm $.$ If the magnification is $-5025,$ what is the focal length of the objective?

$[2$ points$]$

Use $L=d_{i,\text{o}\text{b}\text{j}}+f_{\text{e}\text{y}\text{e}}$ along with the magnification formula for a microscope.

A$)f_{\text{o}\text{b}\text{j}}=0\mathrm{.}048cm$

B$)f_{\text{o}\text{b}\text{j}}=-0\mathrm{.}048cm$

C$)f_{\text{o}\text{b}\text{j}}=-0\mathrm{.}038cm$

D$)f_{\text{o}\text{b}\text{j}}=0\mathrm{.}038cm$