Tax Cut Jobs Act $($TCJA$)$ of $2017$ put constraints on when firms can deduct interest payments. For tax years ending in $2022$ and after, adjustable ble income with be set to EBIT. Which of the following possible scenarios represents the most difficult to model?

Multiple Choice

The fully constrained scenario: For firms that have so much debt that at least $30$ percent of their EBITDA or EBIT is already claimed by existing debt issues for the foreseeable future, the likelihood of being able to take advantage of the interest tax shield on a new debt is either so low or far away in the future that it might not even exist.

The uncertain scenario: For firms that more or less fall in the middle of the other two scenarios, being unable to immediately take full advantage of the interest tax shields during the period when the interest payments are made, but also being expected to be able to use those interest tax shields at some near$-$term time in the future.

None of these choices.

The unconstrained scenario: For most firms, including those with revenues less than $$25$ million per year, the interest on all of their debt will be fully tax deductible.