Ania has written this SimpleStopwatch class. In which line is she measuring the elapsed time?

public class SimpleStopwatch
{
private long startingTime, endingTime;

public SimpleStopwatch()
{
startingTime = System.currentTimeMillis();
endingTime = System.currentTimeMillis();
}

public void start()
{
startingTime = System.currentTimeMillis();
return;
}

public void stop()
{
endingTime = System.currentTimeMillis();
return;
}

public long getDuration()
{
return endingTime - startingTime;
}
}

A. private long startingTime, endingTime;
B. startingTime = System.currentTimeMillis();
C. endingTime = System.currentTimeMillis();
D. startingTime = System.currentTimeMillis();
E. return endingTime - startingTime;