At what proof must rum be distilled according to US regulations?

Rum must be distilled to a proof of 190 according to US regulations. This standard is established under the Federal Standards of Identity for Distilled Spirits, which dictates that for a spirit to be categorized as rum, it must be distilled at a high proof that allows for the retention of the flavor characteristics intrinsic to the fermented sugarcane or molasses used in its production. Distilling at this proof ensures that the final product contains enough of the congeners and flavor compounds essential to rum, while still being suitable for aging and blending.

Distilling at lower proofs, as suggested in the other options, does not align with the regulatory framework for rum production, as doing so could potentially result in a product that may lack the desired flavor profile or authenticity associated with traditional rum.