The following situations involve Shirley Gaas, Bryan Qian, Yu Jiang and Brett Thompson, staff accountants with the CPA firm of Sumikawa and Zhu. 3.Yu Jiang discovered that his client, Cole Company, materially understated its taxable income on last year's tax return. Yu informed his supervisor about this who then told Cole to prepare an amended return. Cole is unwilling to take corrective measures and Yu informed the Internal Revenue Service. 4.Bryan's older brother James is on the internal audit staff of the Zhao Corporation. Bryan is a staff associate on the audit of Zhao. James is located in another city and the two brothers do not interact during the audit. Required For each situation, discuss whether there was or has not been any violation of ethical conduct. Support your answers by reference to the AICPA Code of Professional Conduct