In this reported speech question, you are given the direct question "\"What did you eat last night?\" asked my mother." and must choose the correct indirect version that follows the standard rules of tense and time word changes.

Introduction / Context:
This question tests your skill in converting a simple past wh question into indirect speech, including the correct backshift of tense and adjustment of the time expression. The original direct question is "\"What did you eat last night?\" asked my mother." You must choose the option that accurately reports this question.

Given Data / Assumptions:

• Direct question: What did you eat last night?
• Reporting clause: asked my mother.
• Tense of main verb: did eat (simple past).
• Time expression: last night, referring to the previous evening.

Concept / Approach:
When reporting a past tense question with a past reporting verb, we usually move the tense one step further back. Therefore, the simple past "did you eat" changes to past perfect "had eaten" in the indirect clause. We also rearrange from question word order to statement order and change the time expression "last night" to "the previous night" or "the night before". The wh word "what" remains at the beginning of the clause in indirect speech.

Step-by-Step Solution:
Change the reporting structure to "My mother asked me" because a question is being reported.Keep the wh word "what" at the start of the reported clause.Convert "did you eat" to "I had eaten", changing the person and backshifting the tense.Replace "last night" with "the previous night" to reflect indirect time reference.Combine everything into: "My mother asked me what I had eaten the previous night."

Verification / Alternative check:
The final sentence "My mother asked me what I had eaten the previous night." reads naturally, reflects the correct sequence of events, and uses standard forms found in grammar books. It clearly reports the content of the original question without preserving the question word order inside the subordinate clause.

Why Other Options Are Wrong:
Option A keeps the question word order "what did I eat" inside the reported clause, which is not correct in indirect speech, and also keeps "last night" unchanged. Option C has a similar problem and also fails to indicate whom the question is addressed to. Option D uses "questioned me what I ate last night", which keeps the simple past "ate" and the time phrase "last night", and does not fully follow the expected backshift and time change pattern.

Common Pitfalls:
Many learners struggle with wh questions in reported speech because they try to keep the auxiliary "did" and the original word order. Others remember to change the tense but forget to adjust time expressions like "today", "tomorrow", and "last night". A useful habit is to first rewrite the direct question as a statement and then apply past perfect and time word changes before you add the reporting clause.

Final Answer:
The correct indirect sentence is My mother asked me what I had eaten the previous night.