In English grammar, convert the direct question At what time do the counters close, spoken by the client to the ticket seller, into its correct indirect reported speech form.

Introduction / Context:
This English grammar question tests your understanding of how to change a direct question in the present simple tense into indirect or reported speech. The original sentence is spoken by a client who wants to know the closing time of the counters. In reported speech questions, especially those beginning with a wh word such as what time, we must change the word order, pronouns, and tense correctly while keeping the original meaning intact.

Given Data / Assumptions:

The direct speech sentence is The client said to the ticket-seller, At what time do the counters close.
The reporting verb is said to, which will normally change to asked when reporting a question.
The question begins with the wh phrase at what time, so no auxiliary do or did is needed in the reported clause.
The original question uses present simple do the counters close which usually changes to past simple in indirect speech when the reporting verb is in the past.
We must choose the option that follows standard rules for indirect questions and keeps the meaning correct and natural.

Concept / Approach:
When we convert a direct question to indirect speech, the structure changes from auxiliary plus subject to subject plus verb, just like a normal statement. Wh question words such as what, where, why, and at what time stay at the beginning of the reported clause. Present simple verbs usually shift one step back in tense to past simple if the reporting verb is in the past. In this sentence, do the counters close becomes the counters closed. The reporting verb said to should change to asked for a normal information question, and the phrase to the ticket-seller remains as an object after asked. There is no need for a question mark in the final reported sentence, because the whole sentence becomes a statement about what the client asked.

Step-by-Step Solution:
Step 1: Replace said to with asked because the client is asking a question, not simply making a statement. Step 2: Keep the object of the reporting verb as the ticket-seller, so we have The client asked the ticket-seller. Step 3: Bring the wh expression at what time directly after the object, forming at what time as the connector of the reported clause. Step 4: Change the question word order do the counters close to statement order the counters closed and backshift the tense from present simple close to past simple closed. Step 5: Combine all parts into one complete sentence without a question mark: The client asked the ticket-seller at what time the counters closed.

Verification / Alternative check:
To verify, check whether the indirect sentence correctly answers the question What did the client ask. The sentence The client asked the ticket-seller at what time the counters closed clearly reports the content of the original question. The tense shift from close to closed is standard because the question is reported after it was spoken. The word order at what time the counters closed is correct for an indirect wh clause. There is no extra auxiliary did inside the reported clause, which is important for correct grammar. Everything remains clear and polite, matching typical exam expectations.

Why Other Options Are Wrong:
Option B uses at what time did the counters close in the reported clause, which wrongly keeps the direct question order and auxiliary did. Indirect questions should have statement order. Option C uses will instead of the past form closed, which breaks the normal backshift of tense and suggests a future meaning that the original sentence does not have. Option D keeps the present do in do the counters close and also uses an unnatural phrase inquired to instead of inquired of or asked, so it is not acceptable standard English.

Common Pitfalls:
Learners frequently forget to change the auxiliary do or did into a normal tense form or leave the question word order unchanged when forming indirect questions. Another common mistake is to keep said to instead of using a more appropriate reporting verb such as asked or inquired for questions. Students may also forget to shift the tense from present to past when the reporting verb is in the past. A reliable method is to first imagine the reported clause as a simple statement, then attach the reporting verb and connector at what time to that statement structure.

Final Answer:
The client asked the ticket-seller at what time the counters closed.