Choose the option that fills the blank with the most suitable word:
A preposition is a word which comes before a noun or a pronoun and establishes a relationship between the elements of a clause or words. Option B)for is correct as it indicates a purpose. The other options are wrong as after, with, and in indicate sometime later, inclusion, and the inside of an area respectively. These uses don't fit in the given question. The correct answer is B)for.