I would say the third option, as Fredrick Douglass wrote his as an autobiography, and Huckleberry Finn is an adventure-type story.
As for this problem concerning about a transition between sentences and paragraphs, the most probable and most likely to be the answer out of the options presented would be the third one which is a bridge.
A transition serves as a bridge between sentences and paragraphs. Though they create a divide between them, these transitions do not necessarily indicate that the divide is to cause to present that the two aren't connected to each other. A summary and introduction wouldn't do since a transition functions more and effectively between sentences and paragraphs.
First example: anecdote. The example suggests a narration, particularly through the words "outcome; left alone; etc". The situation also shows that either what preceeds or follows is a experience, that is an action.
Second opinion: expert opinion. This kind of supporting evidence is usually given by professionals, in this case a doctor. The word 'helpful' suggests it is an opinion rather than a fact.
Third example: fact. The use of the present simple tense and the fact that the information is specific shows that it is a fact.
Fourth example: emotional appeal. This kind of supporting evidence uses a variety of words full of emotion. In this example, emotional words include "pledge; striving; and vulnerable". The example appeals to emotions, which is the purpose of this type of evidence.
The theme in a story is its underlying message, or 'big idea.'
In other words, what critical belief about life is the author trying to
convey in the writing of a novel, play, short story or poem? This
belief, or idea, transcends cultural barriers. It is usually universal
in nature. When a theme is universal, it touches on the human
experience, regardless of race or language. It is what the story means.
Often, a piece of writing will have more than one theme.
Think
about some T.V. sitcoms you have seen that you have found trite and
boring. Was there a significant problem in the T.V. show that needed to
be solved? Probably not. In much the same way, if a piece of writing
doesn't have deeper meaning than we can just see on the surface, it is
just as shallow as the T.V. sitcom. In order for writing to be
meaningful and lasting, it needs to have a theme