Concept:Direct speech is converted to indirect speech by changing tense, pronouns, and time/place words. Imperative sentences often use "should" to show duty or responsibility.
Rule / Clue:The sentence has two parts: a statement ("Mohan made this mess") and an imperative ("Let him clear it up"). In indirect speech, the statement's tense shifts to past perfect, and the imperative is expressed using "should" to indicate that clearing up is Mohan's responsibility.
Explanation:The original: "Mohan made this mess. Let him clear it up", said his father.
First, change the statement: "made" becomes "had made", and "this" becomes "that". So: "Mohan had made that mess".
Second, the imperative "Let him clear it up" is not a command but a suggestion/assignment of duty. The best indirect form uses "that he should clear it" to convey responsibility.
Combining: Mohan's father said that Mohan had made that mess and that he should clear it.
Option D matches exactly. Option A uses "proposed" – incorrect because the father isn't proposing but stating a duty. Option B uses "was to clear" – too formal and not the typical indirect speech pattern. Option C uses "suggested" – less authoritative than the father's intent.
Answer:D. Mohan's father said that Mohan had made that mess and that he should clear it.