Identify the correct passive form: "People thought that the despot was corrupt" (49th Special BCS)

Passive transformation of complex sentences containing that-clauses is an advanced grammar skill. Original Sentence Structure: "People thought [that the despot was corrupt]" — Main verb: thought (Past Simple) — Subordinate clause: "that the despot was corrupt" Two valid passive transformations exist: Method 1 — Personal Passive (used here): Subordinate clause subject → new main subject "The despot" becomes the new subject → "The despot was thought to be corrupt." Structure: Subject + was/were + V3 + to be + adjective/noun Method 2 — Impersonal Passive: → "It was thought that the despot was corrupt." Structure: It + was/were + V3 + that-clause Why option (C) is preferred: Both (B) and (C) are grammatically acceptable, but in competitive exams, the Personal Passive form (C) is typically the primary expected answer as it directly transforms the object into the subject. ✗ Option (A): "Had been thought" — wrong tense shift ✗ Option (D): "Is thought" — wrong tense (present instead of past) Source: A Practical English Grammar — Thomson & Martinet; Advanced Grammar in Use — Martin Hewings.