I said theme, but literally am just guessing. Will update if correct! (There was nothing else I could find online regarding this question because of the context they used.)
Gentle or freindly critisism
The answer to #4 is "By" because a preposition word is a word that procedes to a noun or a pronoun. Some examples are "after", "against", "before", "behind", "below", ect... In this case the preposition is "by" and it procedes to the words "royal proclamanation"