Third-person omniscient narrators are likely to be reliable because they're impersonal and know everything about the story they don't care enough about the characters to lie none of the above both "a" and "b"

They're impersonal and know everything about the story

Explanation:

Third person means that they are effectively "outside" the story, and that they are not directly affected or affecting anything in the story.

"Omniscient" means to "know all", and so an Third-person omniscient means that they are not part of the story and that they know all of what is going on.

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i don't know sorry i cannot read a novel in 30 min.

explanation:

but just in case i think the answer is b.