In this sentence transformation item, select the passive voice form of the question "Did they pay the clerks their salary on the first day of the month?".

Introduction / Context:
This question asks you to change an interrogative sentence in simple past tense from active to passive voice. The original sentence, Did they pay the clerks their salary on the first day of the month?, talks about whether a completed payment took place at a specific time. In the passive version, the focus shifts from the people who pay (they) to the clerks, who receive their salary. The correct passive sentence must keep the simple past tense and the sense of a completed transaction that happened on the first day of the month.

Given Data / Assumptions:
The sentence provides these key details.

• Original sentence: Did they pay the clerks their salary on the first day of the month?
• Tense: simple past, indicated by the auxiliary did and base verb pay.
• Subject: they (unspecified payers).
• Indirect object: the clerks.
• Direct object: their salary.
• Time expression: on the first day of the month.

Concept / Approach:
For sentences with two objects, such as the clerks (indirect object) and their salary (direct object), we usually choose the indirect object as the new subject in the passive voice when the focus is on the people receiving something. The simple past passive form uses was or were plus the past participle paid. Because the new subject the clerks is plural, we use were. The question form in simple past passive is made by placing were before the subject. The rest of the sentence, including their salary and the time expression, should remain in a natural order that preserves the original meaning.

Step-by-Step Solution:

Verification / Alternative check:
To check, convert the passive sentence back to active: Were the clerks paid their salary on the first day of the month? becomes Did they pay the clerks their salary on the first day of the month? when we restore the subject they, use the simple past auxiliary did, and change paid back to pay. This matches the original sentence exactly, confirming that the tense, objects, and time expression all correspond correctly.

Why Other Options Are Wrong:
Option B uses are, which is simple present, and changes the time reference from a specific past day to a general routine. Option C changes the subject to the singular clerk and the object to his salary, which alters the number and details of the original sentence. Option D uses were being paid, which suggests an ongoing process rather than the completed action asked about in the original question, and it is also incomplete because it lacks the time expression. Option E uses past perfect had been paid, changing the tense and introducing a prior time relation that is not present in the original simple past question. Only option A keeps the simple past passive structure and the complete meaning.

Common Pitfalls:
One common problem is confusion between simple past and present forms in passive questions, especially when the auxiliary verb comes before the subject. Students sometimes focus only on the correctness of the passive structure and ignore the time reference. Another difficulty arises when there are two objects; candidates may try to convert the direct object into the subject even when the context focuses on people. To avoid this, first decide what the question is really about and then select the object that should become the new subject. Finally, always check whether the passive sentence can be accurately reversed into the original active form without loss of meaning.

Final Answer:
The correct passive question is: Were the clerks paid their salary on the first day of the month?