Correct option is C
The correct passive voice is (c) The journey will be started by them at midnight.
• The sentence “They start the journey at midnight” is commonly used for a scheduled/fixed plan (present form used for near-future schedule).
• In the given options, only (c) gives the correct passive pattern for future meaning: will be + V³.
• Object “the journey” becomes the subject in passive voice.
Grammatical Rule Used (English):
• Passive (Future reference): Object + will be + V³ + by + Subject
Grammatical Rule Used (Hindi):
• Passive में object subject बनता है।
• Future passive की संरचना: will be + क्रिया का तीसरा रूप (V³)
Meanings of the other options:
• (a) “The journey at midnight will be started…” (word order is awkward/less standard)
• (b) “was started” = Simple Past (भूतकाल)
• (d) “was started” = Simple Past (भूतकाल)