Final answer:
The three major Census Metropolitan Areas in Atlantic Canada are Halifax, Moncton, and St. John's, which play significant roles in the region's economy and culture.
Step-by-step explanation:
The major Census Metropolitan Areas (CMAs) in Atlantic Canada are Halifax, Moncton, and St. John's. The CMA of Halifax, located in Nova Scotia, is the largest in the region, recognized for its strong economic base and significant population. Moncton, situated in New Brunswick, is known for its central location in the Maritimes and vibrant cultural scene. Finally, St. John's, the CMA in Newfoundland and Labrador, is noteworthy for being the easternmost city in North America and its historic importance in maritime commerce.
These CMAs are critical to the economic and cultural landscape of Atlantic Canada, and each offers unique characteristics and contributions to the region. Therefore, the correct answer to the question is b. Moncton, Halifax, St. Johns.