Among the listed brands, which one is primarily associated with the production of Rum?

Mt. Gay is a brand primarily associated with the production of rum. Established in Barbados in 1703, it is recognized as one of the oldest rum distilleries in the world. Mt. Gay produces a variety of rums that reflect the island's rich history and tradition of rum-making, offering distinctive flavors that are a result of their unique distillation processes and local ingredients.

In contrast, Knob Creek, Jim Beam, and Johnnie Walker are brands that are renowned for their respective production of bourbon and Scotch whisky. Knob Creek and Jim Beam are both American bourbon brands that focus on the production of grain-based spirits, while Johnnie Walker is a famous Scottish whisky brand known for its blended Scotch whiskies. Therefore, when identifying the brand most closely associated with rum, Mt. Gay clearly stands out.