If the narrator was onmiscient before, that is knew everything, and now has a limited knowledge, then a) it feels more closely to the main character (who also has a limited knowlegde) and b) it usually sticks close to only a single character's perception of the world.
The correct statements are:
<span>The switch in narration increases the proximity of the narrator to the main character.
The reader can perceive information only through the filter of a single character.</span>
The Narrators growth can contrast naive views with the harsh realities of war.
