Please don't be mad if im wrong because im fairly certain it is
C) Participial phrase
The most likely purpose of a document about how to change a tyre is to inform. That is so because such type of document is called a manual, which gives detailed step by step actions to be taken. The type of language used is formal and direct, with no lack to inquire, persuade or entertain but only to give means for the reader to learn how to do what is needed.
The answer is before because prefix of pre is before. For Example preheat
The most appropriate answer is lookng for context clues in the text. since you can identify if the text.is negative the meaning of the word also might be negative.