Which of the following terms refers to "filament" in German?

The term "Heizfaden" is the correct German translation for "filament," particularly when referring to components like those found in light bulbs or heating elements. "Heiz" means "heating," and "faden" translates to "thread" or "filament," encapsulating the concept of a thin, elongated material that carries electrical current or generates heat. This term is commonly used in contexts involving electrical engineering and provides a clear depiction of the filament's function.

In contrast, "Draht" translates to "wire," which refers to a more general and thicker conductor of electricity. "Faser" means "fiber," indicating a much finer thread-like structure, often associated with textiles or biological materials rather than electrical components. "Leiter" translates to "conductor," which is broader and encompasses any material that allows electric charge to flow, not specifically the thin filament used in heating applications. Hence, "Heizfaden" is the most accurate choice to describe "filament" in a technological context.