Whether the term 'controlled substance offense' defined by UNITED STATES SENTENCING GUIDELINES MANUAL § 4B1.2(b) is ambiguous

QUESTIONS PRESENTED 1. Whether the term “controlled substance offense” defined by UNITED STATES SENTENCING GUIDELINES MANUAL § 4B1.2(b) to mean “an offense under federal or state law, punishable by imprisonment for a term exceeding one year, that prohibits the manufacture, import, export, distribution, or dispensing of a controlled substance (or a counterfeit substance) or the possession of a controlled substance (or a counterfeit substance) with intent to manufacture, import, export, distribute, or dispense” is ambiguous? 2. If § 4B1.2(b) is ambiguous, whether the Sentencing Commission’s Commentary to § 4B1.2(b) to define as “controlled substance offense” the “offenses of aiding and abetting, conspiring, and attempting to commit such offenses” is consistent with the text of § 4B1.2(b) and therefore entitled to deference by reviewing courts? ii