The passive form of the sentence :They are going to lock the gate at 7 o'clock .
সমাধান
সঠিক উত্তর: Option D
Be going to যুক্ত active voice -কে passive করার নিয়ম ঃ object কে subject +be verb (am/is/are/was/were ) +going to +be +verb এর past participle form +বাকী অংশ ।