Which of the following statements are
I. Venus has the longest rotation period of any planet in the solar system.
II. In all celestial bodies Venus is the brightest.
III. Venus has no moon.
IV. The surface of Venus is obscured by an opaque layer of clouds made up of sulphuric acid.
A I and II only
B II, III and IV only
C I, III and IV only
D I, II, III and IV