Income tax accounting question

(a) list and explain at least four reasons for provisions of the federal income tax law other than raising revenue for the federal government.

(b) Some of these provisions result in taxpayers with the same income paying different rates and amounts of federal income tax. For example, taxpayers whose income consist of qualified dividends and net capital gains pay less tax than someone who earns the same income as salary. What is the reason for the lower tax rate on qualified dividends and net capital gains?

(c) Define horizontal equity. Is the reason for the lower tax rate on qualified dividends and net capital gains more important than the violation of the principle of horizontal equity that results? Explain in detail.