146. Inheritance

A Sensor class has protected and private members:

class Sensor {
protected:
   int raw_adc;
private:
   int calib_key;
};

class TempSensor : public Sensor {
public:
   void read() {
       raw_adc = 512;     // Line A
       calib_key = 0;     // Line B
   }
};

Which line compiles?