Which of the following is a characteristic of supercell thunderstorms?

Supercell thunderstorms are a distinct class of thunderstorms that have a rotating updraft, known as a mesocyclone. This rotation is a key characteristic, differentiating supercells from regular thunderstorms. The presence of a rotating updraft contributes to the severe weather phenomena often associated with supercells, including tornadoes, large hail, and heavy rainfall. The structure of a supercell is complex, with organized convection and long-lasting intensity due to the sustained rotation, which allows for the vertical development and stability necessary for severe weather events.

Other potential characteristics of thunderstorms, such as whether they are isolated, their movement in relation to fronts, or their formation along boundaries, do not specifically define supercell thunderstorms. While they may exhibit some of those traits under certain conditions, they are not intrinsic features of supercells, making the rotating updraft the most definitive answer in this context.