Al and Amy file a joint return for the 2007 tax year. Their adjusted gross income is $80,000. They had net investment income of $9,000. In 2007, they had the following interest expenses: Personal credit card interest $4,000; Home mortgage interest $8,000; and Investment interest (on loans used to buy stocks) $10,000. What is Al and Amy's interest deduction for the 2007 tax year?
1- $17,000
2- $8,000
3- $12,000
4- 18,000