The answer is A: applying broad knowledge to specific examples.
Deductive reasoning is a logical process by which one can reach a conclusion of a specific nature by means of premises of a broader nature, or to be more precise, premises that are theoretically general but allowing for its application, following logical rules or argumentation or thought, to a specific case, instance or sample.
Yes because maybe one day we will need to know what is out there.
The answer to this question is a metaphor
Remember the sacrifices of the people who fought at Gettysburg.