Which type of SIGMET is associated with volcanic eruptions or ash clouds?

The option that identifies the type of SIGMET associated with volcanic eruptions or ash clouds is Non-Convective SIGMET. Non-Convective SIGMETs are issued to indicate significant weather phenomena that are not related to convective activity but can still present hazards to aviation. These can include severe turbulence, dust storms, or volcanic ash clouds.

Volcanic eruptions create ash clouds that can be dangerous for aircraft, as ash can damage engines and reduce visibility. Non-Convective SIGMETs serve to warn pilots of such conditions, ensuring that they can take necessary precautions to avoid flying through these hazardous areas.

Other choices, while relevant in a broader weather context, do not pertain specifically to volcanic activity. Convective SIGMETs focus on severe thunderstorms and related phenomena, AIRMETs address weather that could potentially affect smaller aircraft but do not cover volcanic ash specifically, and METARs are routine aviation weather reports that provide current weather information rather than warnings of significant weather events like volcanic ash clouds.