Which of the following groups of words is a sentence fragment?
a) we stopped; she didn't.
b) stopping by the garden, we saw that the flowers were in bloom.
c) when we stopped by the garden.

Sentence fragment is defined as the set of words that look like sentences but actually they are not.For a sentence there should be a absolute clause.
therefore,
first and second option have absolute clause while third one is sentence fragment.
hence the right option is C) When we stopped by the garden.

If the author had focused his attention equally on the thoughts, actions, and feelings of all three of these characters, the point of view would be called the omniscient third person.

Explanation:

When we write a novel or a short story we can use different points of view. These are nothing more than the perspectives by which the story will be told: first, second and third person.  When the author chooses to narrate his story using the third person, he still has to choose between two points of view: omniscient or limited.

From this perspective, in the omniscient third-person view the narrator of the story knows all the feelings and thoughts of the characters. This style of narrative opens up a gigantic wealth of opportunities for the writer. The narrator may include feelings and tendencies of personality that the character itself does not know or refuses to accept. There are no secrets for the writer. He can peer into the depths of the soul, embrace every detail, and assume the esteemed position of what he really is: the creator of history.