In this English grammar question on voice, a sentence in the active voice is given in the simple past tense. Out of the four alternatives, select the option that best expresses the same idea in the passive voice: No one answered my call for help.

Introduction / Context:
This question focuses on converting a negative simple past active sentence into a passive sentence. The original statement "No one answered my call for help" emphasises the absence of a response from any person. In the passive form, the focus moves to "my call for help" as the subject, and the idea that no person answered is preserved using a negative passive construction. This type of transformation is important for expressing emphasis and style variation in English.

Given Data / Assumptions:

• The verb "answered" is in simple past tense.
• The subject is the negative indefinite "No one".
• The object is "my call for help".
• The sentence is negative, highlighting that nobody responded.
• The passive form must keep both the past time reference and the negative meaning.

Concept / Approach:
In simple past tense, passive voice is formed using "was / were + past participle". The object "my call for help" becomes the subject in the passive sentence. Since "call" is singular, we use "was". The past participle of "answer" is "answered". To keep the negative meaning, we combine "was not answered" with the phrase "by anyone" instead of using "no one" as the subject. This is the typical way to express the same idea in passive voice while preserving the sense that nobody responded.

Step-by-Step Solution:
First, identify "my call for help" as the object that will become the subject of the passive sentence. Second, recognise that the tense is simple past, so the correct passive auxiliary for a singular subject is "was". Third, form the passive verb phrase "was not answered" to show the negative past action. Fourth, add the phrase "by anyone" to express that no person answered the call. Fifth, assemble the full sentence "My call for help was not answered by anyone" and confirm that the meaning matches the original.

Verification / Alternative check:
The passive sentence "My call for help was not answered by anyone" states clearly that the call remained unanswered and that no person responded. The simple past passive "was not answered" corresponds to "No one answered" in active voice. The subject "my call for help" now carries the focus, which is a common reason to choose passive voice. Comparing both versions shows that the time, negativity, and overall meaning are preserved, with only the grammatical structure changed.

Why Other Options Are Wrong:
Option A uses an awkward phrase "Answering my call for help was not done by anyone", which is grammatically possible but not the straightforward passive form the question targets. Option B changes the perspective to "I have not got any answer" and even shifts to present perfect, altering both tense and focus. Option C describes the act of calling and then adds a separate clause about no answer, which changes the structure and emphasis. Only option D uses the clean and direct form "My call for help was not answered by anyone" that best reflects the original sentence in passive voice.

Common Pitfalls:
Learners may be tempted to keep the negative subject "No one" and try to force it into a passive sentence, which often leads to awkward or incorrect structures. Another common issue is changing the tense to present perfect or using complicated nominal expressions. Some students also omit "by anyone", which can slightly weaken the sense that nobody at all answered. To avoid these problems, always let the original object become the subject, keep the tense the same, and express the negative idea clearly with "not" and an appropriate phrase like "by anyone".

Final Answer:
The option that correctly expresses the sentence in the passive voice is: My call for help was not answered by anyone.