Final answer:
Isabella can deduct $2,875 as her itemized deduction for medical expenses, which is the amount of her total medical expenses ($6,250) minus 7.5% of her AGI ($3,375).
Step-by-step explanation:
The question is about calculating the itemized deduction for medical expenses on Isabella's tax return. In the tax year 2018, taxpayers could deduct the portion of medical expenses that exceeded 7.5% of their adjusted gross income (AGI). Isabella's AGI is $45,000, and her total medical expenses are the sum of her health insurance premiums ($500 per month for 12 months) plus her doctor bills and over-the-counter medications, which is $6,000 + $200 + $50 = $6,250.
7.5% of Isabella's AGI is $45,000 * 0.075 = $3,375. Since her medical expenses ($6,250) exceed this amount, she can deduct the difference on her tax return. Therefore, Isabella's medical expense deduction is $6,250 - $3,375 = $2,875.