Identify the part of the following sentence in which there is an error:
Ram told (A) / me that (B) / he has (C) / lost his book. (D)

Correct option is C

Error part: (c) he has
Correct form: he had / he had lost
Detailed explanation:
• Reporting verb “told” is in past. In reported speech, when the reporting verb is past, the tense in the subordinate clause generally shifts back.
• “has lost” is Present Perfect, but it should become Past Perfect: had lost.
Correct sentence: Ram told me that he had lost his book.
Grammatical rule (English):
• Past reporting verb ⇒ Present Perfect → Past Perfect (has/have + V³ → had + V³).
व्याकरणिक नियम (Hindi):
• यदि reporting verb past हो, तो reported clause का tense पीछे जाता है: has/have + V³ → had + V³।
Hence, option (c) is the correct answer.