Answer:
Prepositions must always be followed by a noun or pronoun. That noun is called the object of the preposition. Note that a verb can't be the object of a preposition.
due dilligence is the act and being percise or careful in order to fufuil a legal requirement.
* Im kind of confused becuse of how you worded it but I think youre aking about dilligence now? And not due dilligence? *
You can be more dilligent in class by taking your time and putting more effort into your action/work
D I think beacuse he wanted to read the book
A folktale because those always have stuff like that