Investors or company cost of debt

Hi John, I am confused as to how to determine whether it is the investors or the company when calculating the MV on redeemable debt. Question 22 in the september 2016 mock specifically. I have read that question from the companies perpective and included corporation tax whereas that is wrong. I know in your lecture on this you do say that it is the company ones where we are more likely to be examined on so was wondering how do we know which is which? There is a similar question in section a where i included tax so effectively 4 marks lost quite stupidly!