**Rule**: For a Present Continuous Tense sentence, the passive structure is **Object + is/am/are + being + V3 + by + Subject**.

- **Correct Answer (a)**: The direct object 'the lesson' becomes the subject. The passive verb 'is being explained' is correct, and the indirect object is expressed through the prepositional phrase 'to the students'.
- **Incorrect Answer (b)**: This structure, where the indirect object becomes the subject, is grammatically incorrect with the verb 'explain'. You cannot 'explain a person'.
- **Incorrect Answer (c)**: This incorrectly changes the tense to Present Perfect.
- **Incorrect Answer (d)**: This incorrectly changes the tense to Simple Present.

**Rule**: For an interrogative sentence in the Present Continuous Tense starting with a 'Wh-' word, the passive structure is **Wh- word + is/am/are + object + being + V3 + by + subject?**

- **Correct Answer (a)**: The 'Wh-' word 'Why' remains at the beginning. The new subject 'you' takes the verb 'are', followed by 'being' and the past participle 'ignored'.
- **Incorrect Answer (b)**: This incorrectly changes the tense to Past Continuous.
- **Incorrect Answer (c)**: This has incorrect word order for a question; the auxiliary verb 'are' should come before the subject 'you'.
- **Incorrect Answer (d)**: This incorrectly changes the tense to Present Perfect.

**Rule**: For an interrogative sentence in the Present Perfect Tense starting with 'What', the passive structure is **What + has/have + been + V3 + by + subject?**

- **Correct Answer (c)**: 'What' remains at the beginning and acts as the subject. The passive verb form 'has been decided' is correct for the Present Perfect Tense.
- **Incorrect Answer (a)**: This incorrectly changes the tense to Simple Past.
- **Incorrect Answer (b)**: This incorrectly changes the tense to Present Continuous.
- **Incorrect Answer (d)**: This incorrectly changes the tense to Past Perfect.

**Rule**: For an interrogative sentence in the Present Continuous Tense starting with 'What', the passive structure is **What + is/am/are + being + V3 + by + subject?**

- **Correct Answer (c)**: The 'Wh-' word 'What' remains at the beginning and acts as the subject. The passive verb form 'is being cooked' is correct for the Present Continuous Tense.
- **Incorrect Answer (a)**: This incorrectly changes the tense to Past Continuous.
- **Incorrect Answer (b)**: This incorrectly changes the tense to Simple Present.
- **Incorrect Answer (d)**: This incorrectly changes the tense to Present Perfect.

** Present continuous → past continuous. “Now” → “then.”

** Present perfect → past perfect.

** “May” → “might.” “Next week” → “the following week.”

** Imperative in indirect → “told/asked + object + to + verb.” Pronoun “your” → “our.”

** “Will” → “would.” “Tomorrow” → “the next day.”

** Past continuous → past perfect continuous. The second clause “when he came” remains unchanged.