To solve this question, we need to understand the meaning and usage of prepositions of place and direction.
Prepositions of place describe the location of something, while prepositions of direction describe the movement or direction of something.
Let's analyze the given sentence and determine the correct preposition:
Customers crowded _____ the ATM counter to withdraw money.
The sentence talks about the location of the customers in relation to the ATM counter. So, we need to choose a preposition of place.
The correct answer is B: at because:
- "At" is used to indicate a specific location or position.
- In this case, the customers are physically present and gathered around the ATM counter to withdraw money.
- "At" accurately describes the location of the customers in relation to the ATM counter.
Other options explained:
- A: under - This preposition is used to indicate something beneath or below an object. However, in this context, it does not convey the correct meaning as the customers are not positioned underneath the ATM counter.
- C: on - This preposition is used to indicate something on top of an object. However, in this context, it does not convey the correct meaning as the customers are not positioned on top of the ATM counter.
- D: next to - This preposition is used to indicate something adjacent or beside an object. While the customers may be positioned close to the ATM counter, it does not accurately describe the crowded situation mentioned in the sentence.
Therefore, the correct preposition to fill in the blank is at.

Explanation:

The correct preposition to use in this sentence is "at".

Prepositions of place:
Prepositions of place are used to indicate the location or position of something in relation to another object. In this sentence, we are talking about the location of the customers in relation to the ATM counter.

Prepositions of direction:
Prepositions of direction are used to indicate the movement or direction of something or someone. In this sentence, we are not talking about the movement or direction of the customers, but rather their location in relation to the ATM counter.

Correct answer:
The correct preposition to use in this sentence is "at" because it indicates the location of the customers in relation to the ATM counter. The customers are crowded at the ATM counter, which means they are in close proximity to it.

Incorrect options:
- "Under" is incorrect because it suggests that the customers are beneath the ATM counter, which is not the intended meaning of the sentence.
- "On" is incorrect because it suggests that the customers are on top of the ATM counter, which is also not the intended meaning of the sentence.
- "Next to" is incorrect because it suggests that the customers are beside the ATM counter, rather than crowded around it.

Conclusion:
The correct preposition to use in this sentence is "at". The customers are crowded at the ATM counter to withdraw money, indicating their location in relation to the counter.