The completed analogy would be crocodilian: crocodile
A crocodilian is a family of reptiles that includes alligators, caimans, crocodiles, and 23 other species.
Inferior. 'Sub' as a prefix means 'under' or 'below', and indicates that the subject is in a relatively small proportion.
The answer is B) due to the fact that it's a good topic to start off a paragraph with
Hope this helped :)