Extra exam question E7D12

WhyThe dropout voltage of a linear voltage regulator is the minimum input-to-output voltage required to maintain regulation. A linear voltage regulator's dropout voltage is the minimum difference between input and output voltage that must be maintained for the regulator to keep working properly and hold regulation, once the input-to-output difference falls below that minimum, the regulator can no longer maintain its rated output, answer C. It isn't a minimum input voltage tied to power dissipation, isn't a maximum output variation over the input range, and isn't a maximum output decrease at rated load, those describe other regulator specifications like load regulation.