Use the following information to answer the question$($s$)$ below.

Nielson Motors has a debt $-$ equity ratio of $1\mathrm{.}8,$ an equity beta of $1\mathrm{.}6,$ and a debt beta of $0\mathrm{.}20.$ It is currently evaluating the following projects, none of which would change Nielson's volatility.

$\backslash$table$[[$Project$,1,2,3,4,5],[$Investment$,100,75,120,60,80],[$NPV$,23,12,18,15,14],[($All amounts are in $millions.$),,,,,]]$

The total debt overhang associated with accepting project $4,$ is closest to:

A$.$ $$15\mathrm{.}0$ million

B$.$ $$0$ million

C$.$ $$38\mathrm{.}6$ million

D$.$ $$13\mathrm{.}5$ million