When the pressure of the gas in a discharge tube is gradually lowered. I. there is a violet glow in the tube II. the glow in the tube splits into bands which get further apart. III, the glow and the bands eventually disappear and there is a green fluorescence in the tube. IV. the tube breaks into pieces. Which of the following are correct?

• A.I and II only
• B.I and III only
• C.I and IV only
• D.I, II and III only
• E.I, II III and IV