Sam's Year 2 taxable income was $175,000 with a corresponding tax liability of $30,000. For Year 3, Sam expects taxable income of $250,000 and a tax liability of $50,000. In order to avoid a penalty for underpayment of estimated tax, what is the minimum amount of Year 3 estimated tax payments that Sam can make?

• $50,000
• $30,000
• $45,000
• $33,000