In the following question, a sentence is given in the Active voice. Choose the option that correctly expresses the same idea in the Passive voice: He saw him conducting the seminar on personality development.

Introduction / Context:
This question checks understanding of the transformation between active and passive voice in English grammar. The original sentence describes someone seeing a person in the process of conducting a seminar. The passive form needs to preserve the idea that the person was observed while carrying out the action of conducting. Many students struggle with voice change when continuous or progressive meanings are involved, so careful attention to meaning is required rather than a mechanical swap of subject and object.

Given Data / Assumptions:
- Original sentence in active voice: He saw him conducting the seminar on personality development.
- We need an equivalent sentence in passive voice that keeps the sense of continuous action.
- The observer in the original sentence is not important in the passive option and can be omitted.
- Four alternatives are given, and we must pick the one that best preserves the original meaning.

Concept / Approach:
In voice change, the object of the active sentence usually becomes the subject of the passive sentence. The tense and aspect remain as close as possible in meaning. The original sentence means that someone saw a man while he was conducting a seminar. In passive form, the focus shifts to the man, who was seen, not to the person who saw him. It is also common to omit the agent if it is not important, especially in simple reporting sentences where the doer is obvious or irrelevant.

Step-by-Step Solution:
Step 1: Identify the logical agent and object. The essential meaning is that a person (unspecified in the best passive form) saw him, and he was conducting a seminar.Step 2: In passive, the person who was being observed, that is he, should become the subject. So the passive sentence has to begin with He was seen.Step 3: The continuous sense conducting the seminar on personality development must be preserved. The phrase conducting the seminar on personality development should follow He was seen.Step 4: The option He was seen conducting the seminar on personality development exactly captures this meaning without forcing an unnatural infinitive structure.Step 5: Therefore the correct passive voice is He was seen conducting the seminar on personality development.

Verification / Alternative check:
We can check the correctness by paraphrasing. The sentence He was seen conducting the seminar on personality development can be reworded as Someone saw him while he was conducting the seminar on personality development, which matches the original statement. The tense, focus and meaning are consistent. The observer is not mentioned, but that is acceptable in passive constructions when the agent is not important or is clear from context.

Why Other Options Are Wrong:
- He was seen by me to conduct the seminar on personality development is grammatically possible but does not match the original subject, because the original does not explicitly mention me. It also sounds more formal and slightly different in emphasis.
- He saw the seminar on personality development being conducted by him shifts the focus to the seminar and introduces confusion by suggesting that he saw the seminar itself rather than the person conducting it.
- He saw the seminar on personality development to be conducted by him suggests a future or planned action, not an action that was already in progress, so it changes the meaning.

Common Pitfalls:
Students often think that every passive must include a by phrase that names the agent, but that is not always necessary. Another mistake is to change the structure into an infinitive, as in to conduct, which can alter the time reference. It is safer to keep the progressive or continuous sense when the original sentence shows an action in progress. Always check whether the passive sentence can be expanded back into a natural active sentence that matches the given one in sense and time.

Final Answer:
The correct passive voice form is He was seen conducting the seminar on personality development.