As the Owner of a Women's Clothing Store, Caroline Lipscomb

As the owner of a women's clothing store, Caroline Lipscomb has an income of $75,000. She pays $30,000 per year in taxes and another $17,000 per year in grocery bills, house mortgage, and car payment. Last year she went to Italy and spent an additional $4,000. What was Caroline's discretionary income last year?

A) $45,000.
B) $75,000.
C) $26,000.
D) $28,000.
E) $24,000.