consider the word "omniscient." if you aren't familiar with it, you might recognize the prefix--omni. herbivore, carnivore... omnivore. what do omnivores eat? other plants or animals, all. omni- is a prefix meaning all. that could have given you a hint. a second hint could have been "third-person"; this type of point of view is generally objective, because it's told from the view of a third party who isn't directly involved with the action of the story.
an omniscient point of view means "all-knowing." choice A is incorrect because it states that a third-person omniscient focuses on ONE character's thoughts and actions--if the view is omniscient, it is all knowing and states every character's thoughts. it isn't limited to a single character. a story that uses "you" or "yours" is in second person pov, because it speaks directly to a second person. this, again, is not third-person OR omniscient. choice C is incorrect for the same reasons as choice A.
choice D is your only remaining answer, and it is correct. a third-person omniscient narrator informs the reader of all the thoughts and actions within a scene, between every character.
