Answer: Considering the given options the least appliable for a Certified Public Accountant (CPA) research on tax issues would be the Committe Report of the House because the focus of these registers remain moreover on investigations accompanying chamber action over legislative measures, internal matters and House conferences, although it does register the perspective of the Congress - House or Senate - on some policy issues that may include information on taxes. But it would not be a primary research source.
Explanation: Ways and Means Committe is the main one on elaborating taxation ruling (very pertinent for the issue); the Notices of Proposed Rulemaking has great chance to beam light over any financial directives being prompted by the Congress; the Senate Finance Committe deals scopefully with national fiscal health, employment policies and competitiveness - which documents could reveal excess or lack of taxation in some areas - ; and finally, the Congressional Record is an up to date registration that could reveal any late or actual government attemp to change taxation ruling.