Choose the option that fills the blank with the most suitable word:
The letter arrived _____ an early date.
Answer : C
Prepositions are words that indicate relationships with the other words in the sentence. Prepositions of time are used to denote time in a sentence.
Let's look at the usage of various alternatives in the option as preposition of time:
Upon reading the sentence in the question, we understand that a specific time / "date" has been mentioned.
Therefore the suitable preposition here is "after".
Thus, the correct complete sentence is:
The letter arrived AT an early date.