The following question tests recognition of the active form of a sentence originally written in the passive: "Had work been resumed by the labourers before the manager arrived?". Choose the correct active alternative.

Introduction / Context:
Here the direction is to change a passive interrogative sentence in the past perfect tense into its correct active voice form. The original sentence, Had work been resumed by the labourers before the manager arrived?, uses a passive construction in question form. In competitive exams, such questions check whether you can recognise the original underlying active structure and reproduce it accurately, with the correct tense, auxiliary verbs, and word order. The target is a past perfect interrogative in active voice with labourers as the subject and work as the object, while the time clause before the manager arrived remains unchanged.

Given Data / Assumptions:
The passive sentence gives the following information.

• Original passive: Had work been resumed by the labourers before the manager arrived?
• Tense: past perfect, as seen in had been resumed.
• Grammatical subject in passive: work.
• Agent in passive: by the labourers.
• Time clause: before the manager arrived.

Concept / Approach:
To change a sentence from passive to active voice, we reverse the process used for active to passive. The passive subject becomes the object in the active sentence, and the agent in the by phrase becomes the subject. In past perfect tense, the active form uses had plus the past participle of the main verb. In question form, had comes before the subject. Therefore, the structure we want is: Had + subject (the labourers) + past participle (resumed) + object (work) + time clause (before the manager arrived). The meaning of the sentence should remain that the labourers had already resumed work before the manager came.

Step-by-Step Solution:

Verification / Alternative check:
To check the accuracy, we can convert the active sentence back into passive voice. Starting from Had the labourers resumed work before the manager arrived?, we move work to the subject position and place the labourers in a by phrase after the verb, giving Had work been resumed by the labourers before the manager arrived?. This matches the original question exactly, confirming that we have chosen the correct active alternative. The tense (past perfect), the sense of completed action before another past event, and the interrogative pattern are all preserved.

Why Other Options Are Wrong:
Option A uses Have the labourers resumed work, which is present perfect, not past perfect, and so does not reflect the same time relation as had been resumed. Option C, Had they resumed the work before the manager came?, changes the subject to they and uses came instead of arrived, and it also sounds less precise; although similar in meaning, it does not match the structure that clearly corresponds to the given passive sentence. Option D introduces not, which changes the meaning and suggests that the workers perhaps did not resume work, whereas the original question is neutral. Option E uses Did the labourers resume work, which is simple past and does not show the sense of completion before another past event. Therefore, only option B is fully correct.

Common Pitfalls:
Learners often miss tense distinctions between simple past, present perfect, and past perfect, and they may select an option simply because it sounds natural. Another common mistake is ignoring the negative word not or additional modifiers that can change the meaning. When dealing with passive to active transformations, always pay close attention to the auxiliary verbs had, has, have, and be sure that the new sentence can be converted back to the original form without any change of meaning. For interrogative sentences, make sure the auxiliary comes before the subject in both active and passive forms. Practising these patterns helps you answer such questions quickly in exams.

Final Answer:
The correct active voice sentence is: Had the labourers resumed work before the manager arrived?