Company Valuation – APV- Debt

Hello sir,

The Kaplan study kit states that when we value a company using the APV method to:

add present value of the tax saved as a result of the debt finance USED IN THE ACQUISITION.

they have gone on to use the debt that the target company already has in its capital to value the tax shield and not the debt the parent company is about to raise to purchase the target company.

So does that mean when valuing a target company using APV we use the debt the target company already has, for the tax shield?

I thought that the practical thing would be (like for a project appraisal) to use the debt finance the parent company is about to raise to finance the acquisition to value the tax shield?