Final answer:
New Brunswick has the highest proportion of French speakers among the four Atlantic provinces due to its significant Francophone population and its status as the only officially bilingual province in the area, with a rich Acadian cultural heritage.
Step-by-step explanation:
Among the four Atlantic provinces, New Brunswick has the highest proportion of French speakers. This can be attributed to its historical context and geographical location. New Brunswick is one of Canada's three Maritime provinces and is the only officially bilingual province with French and English being co-official languages.
The proportion of French speakers in the Atlantic provinces reflects the historical settlement patterns and the cultural heritage of the area. In the 18th century, many French settlers, known as Acadians, were deported from the Maritime Provinces; however, New Brunswick still retains a significant Francophone population. The Acadians are a key part of the cultural and linguistic landscape of the province to this day.
Moreover, Acadian culture is vibrant and influential in New Brunswick, and this province is often considered part of the core of French Canada, extending from Quebec to the Atlantic coast. New Brunswick's bilingual status, along with its French-speaking communities, differentiates it from the other Atlantic provinces like Prince Edward Island, Newfoundland and Labrador, and Nova Scotia where the French-speaking populations are smaller.