Identify the correct tense form of the highlighted part in the given sentence.
I had finished writing the letter when he arrived.

Correct option is D

Correct tense: (d) Past Perfect
Meaning (in detail):
• Past Perfect is used to show that one action was completed before another past action.
• Hindi: भूतकाल की दो घटनाओं में जो पहले पूरी हो जाए, उसके लिए Past Perfect।
Identification:
• “had finished” = had + V³ → Past Perfect.
• “arrived” is simple past; the finishing happened before arrival.
Grammatical rule (English):
• Past Perfect = had + V³ (earlier past action)
व्याकरणिक नियम (Hindi):
• Past Perfect की रचना: had + V³; दो past actions में पहले वाली क्रिया के लिए उपयोग।
Hence, option (d) is the correct answer.