B. use a familiar concept to communicate an idea
Basically, Passage 2 states the hypothesis that spotted green pigeon is a descendant of an island hopping bird and throughot the article, it provides evidence for this statement.
The discovery is that, since the DNA found in a green pigeon's feather was fragmented and they had to analyze only parts of it, the bird had an unique sets of DNA which distinguish it from other members of the pigeon species.
These analyzed parts of DNA are refered to as "mini barcodes".
Since target audience for this article might not be fully familiar with the concept and functions od DNA, researchers used a more familiar concept of barcodes as an analogy to communicate their idea and explain their discovery.
The uncertainty of inventiveness and futuristic ideas usually deal with science and technology.
Inventibility is something uncertain which promotes a risk in any system in which it is inserted. With that, we can naturally associate it with the maintenance of science and technology, because both are in need of inventing new creations, which may or may not be effective for the defeat of uncertainties and the creation of certainties.
This is usually linked to futuristic ideas, which may not fit in today's society, but which impose improvements, or not, for societies in the future. Leading to the creation of more technologies and more sciences.