Fill in the blank with a suitable preposition:
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 D)until is correct as it means up to. The other options are wrong as bye, at, and since means wishing goodbye, a specific location, and a duration with its starting point of time given respectively. These uses don't fit in the given question. The correct answer is D)until.