Answer: Option D
A preposition is a word that shows the relationship between a noun or pronoun and other words in a sentence. In this sentence, the customer is performing an action on the table, and we need to use a preposition to show the relationship between the two.
The prepositions "into" and "on" both suggest a position of the fist relative to the table, but they don't convey the force or impact of the action. The preposition "at" can be used to indicate a target or direction, but it doesn't accurately describe the physical contact between the fist and the table.
The preposition "against", on the other hand, is commonly used to show physical contact or collision between two objects. It is the most appropriate preposition to use in the given sentence as it conveys the forceful impact of the customer's fist on the table.
Therefore, the correct answer is option D) against.
Key takeaways:

• Prepositions are words that show the relationship between a noun or pronoun and other words in a sentence.
• The choice of preposition depends on the context of the sentence and the intended meaning.
• In this sentence, the preposition "against" is the most appropriate as it accurately describes the physical contact and impact of the customer's fist on the table.