While Discussing Greenhouse Gas (GHG) Emissions and Diesels, Technician a Says

While discussing greenhouse gas (GHG) emissions and diesels, Technician A says that carbon dioxide emissions are regulated through fuel economy standards. Technician B says that there are no direct carbon dioxide (CO₂) standards in North America for diesel-powered vehicles. Who is correct?

A) Technician A
B) Technician B
C) Both A and B
D) Neither A nor B