The graph illustrates how the current $I$ in components $X$, $Y$ and $Z$ changes with potential difference $V$. Which row correctly names the components?
- AMetallic conductor at constant temperature: $X$, Semiconductor diode: $Z$, Filament lamp: $Y$
- BMetallic conductor at constant temperature: $Y$, Semiconductor diode: $X$, Filament lamp: $Z$
- CMetallic conductor at constant temperature: $Y$, Semiconductor diode: $Z$, Filament lamp: $X$
- DMetallic conductor at constant temperature: $Z$, Semiconductor diode: $Y$, Filament lamp: $X$