Cathy is the President and sole shareholder of Boxer, Inc., a regular corporation. The corporation reported taxable income of $435,000 after deducting Cathy's $800,000 salary. If the IRS disallowed $550,000 of the salary as unreasonable compensation, the corporation's regular income tax will change by a:

A. $115,500 increase B. $175,000 increase C. $175,000 decrease D. $115,500 decrease Please show steps and reasoning. Thank you.