The correct answer is letter D
The omniscient narrator tells the story in 3rd person and sometimes allows certain intrusions to narrate in 1st person. He knows everything about the characters and the plot, knows what goes on inside the characters, knows their emotions and thoughts.
He is able to reveal his inner voices, his flow of consciousness, in the first person. When this happens, the narrator makes use of free indirect speech. Thus, the plot becomes fully known, the antecedents of the actions, their lines, their assumptions, their future and their consequences.