Final answer:
The Tax Cuts and Jobs Act (TCJA) changed the deductible amount for mortgage interest. The interest on the first $750,000 of mortgage debt is now deductible.
Step-by-step explanation:
The correct answer is b) 750,000. One change brought by the Tax Cuts and Jobs Act (TCJA) is that only the interest on the first $750,000 of mortgage debt is deductible. This applies to new mortgages taken out after December 15, 2017. Prior to the TCJA, the limit was $1 million.