In the following question, the sentence is given in direct speech. Select the option that best expresses the same meaning in indirect (reported) speech: I do not know the answer. Do you? she asked.

Introduction / Context:
This question examines the rules of changing direct speech into indirect or reported speech. The original direct speech consists of two sentences: a statement and a question. The speaker admits that she does not know the answer and then asks another person whether he or she knows it. In reported speech, both parts must be combined in a grammatically correct way that keeps tense, pronouns and meaning consistent. The correct option will show accurate tense backshift and appropriate linking.

Given Data / Assumptions:
- Direct speech: I do not know the answer. Do you? she asked. - Speaker is she, who is talking to another person, the listener. - Reporting verb can be said or asked, and indirect speech will likely join the two sentences. - The reporting is in the past, so present tense forms will normally move one step back.

Concept / Approach:
Key rules for converting direct speech to indirect speech include tense backshift, change of pronouns and adjustment of question structure. When the reporting verb is in the past tense, present simple usually becomes past simple in reported speech. Pronoun I becomes she and you becomes I or he or she depending on who is being spoken to. In reporting a question, the auxiliary do is dropped and the order changes to normal statement order, introduced by if or whether. Here we must join the statement I do not know the answer with the question Do you? into one smooth reported sentence.

Step-by-Step Solution:
Step 1: Report the statement I do not know the answer. Since the reporting verb is in the past, do not know changes to did not know. The pronoun I refers to she, so it becomes she. This gives she said that she did not know the answer. Step 2: Report the follow up question Do you? This is a short form of Do you know the answer. In indirect speech, the auxiliary do is removed and normal statement order you knew the answer is used. The pronoun you refers to the listener, that is, me in the indirect version. Step 3: Introduce the reported question with if or whether. With pronoun change, the question becomes asked me if I did or asked me if I knew the answer. Both preserve the sense of asking whether the listener knew the answer. Step 4: Combine both parts into one sentence: She said that she did not know the answer and asked me if I did. This option uses correct tense, pronoun change and question reporting. Step 5: Verify that no unnecessary colloquial expressions such as was not knowing or present tense forms like I know remain, since they would break standard reported speech rules.

Verification / Alternative check:
Check option C carefully: She said that she did not know the answer and asked me if I did. We can reconstruct the direct speech: She said, I do not know the answer. Do you? This matches the original sentence in both content and intention. The tense backshift is correct, and the sequence of reporting her own lack of knowledge followed by her question to the listener is preserved. There are no tense inconsistencies or grammatically incorrect progressive forms such as was not knowing.

Why Other Options Are Wrong:
Option A: She asked me whether I knew the answer which she did not. This structure is clumsy and slightly unclear. It suggests that she did not know which answer, and it does not clearly convey that she said she did not know the answer before asking. Option B: She said that she did not know the answer and asked if I know it. The second clause keeps know in present simple after a past reporting verb, which breaks the tense backshift rule. Option D: She told me that she was not knowing the answer but wondered if I know. The phrase was not knowing is ungrammatical in standard English for a state verb, and again know remains in present simple, making the sentence incorrect.

Common Pitfalls:
Learners often forget to adjust the tense in the second clause of a combined reported sentence or they use progressive forms with state verbs like know, which is not standard usage. Another frequent error is to omit the reporting of the question completely or to use wrong connectors such as and did I know instead of asked me if I knew. To avoid these issues, always apply tense backshift consistently to every clause and use if or whether when reporting yes or no questions.

Final Answer:
The correct indirect speech version is She said that she did not know the answer and asked me if I did., so option C is correct.