Final answer:
Randle Reef is an area in Hamilton that represents a significant environmental concern in Canada due to contaminated sediment from industrial pollution.
Step-by-step explanation:
The area in Hamilton that is one of Canada's most prominent areas of environmental concern is B. Randle Reef. This site in Hamilton Harbour has been known for its severely contaminated sediment, which is a result of over a century of industrial pollution. The contamination is primarily coal tar, a by-product of steel making, which is harmful to aquatic life and poses risks to the surrounding environment. In response, a massive clean-up project has been underway to remediate the site, which involves containing the toxic sediment and creating new fish habitats. This effort reflects the significant challenges and actions being taken to address environmental issues in industrial regions like Hamilton.