Final answer:
The decisions of the U.S. Tax Court are not included in RIA's American Federal Tax Reports; whereas, the decisions of the District Courts, Supreme Court, and U.S. Court of Federal Claims are included. So, the correct answer is option b.
Step-by-step explanation:
The question asks which court's decisions are not included in RIA's American Federal Tax Reports (AFTR or AFTR2d). Looking at specialized federal courts and the types of cases they handle, the answer to this question would be the U.S. Tax Court.
While the District Courts (federal district courts), the Supreme Court, and the U.S. Court of Federal Claims do have their decisions reported in AFTR, the U.S. Tax Court does not, as it is a specialized court handling tax matters and operates under a different reporting system.