Answer:
c. District Court opinions carry less weight than Tax Court opinions.
Explanation:
"Judges have developed various interpretive tools in the form of canons of construction. Canons broadly fall into two types. "Language," or "linguistic," canons are interpretive "rules of thumb" for drawing inferences based on customary usage, grammar, and the like."
Reference: Demand Progress. “Statutory Interpretation: General Principles and Recent Trends.” EveryCRSReport.com, Congressional Research Service, 24 Sept. 2014