(B), (A), (D), (C) -> This creates the correct sentence: "No sooner had the student reached the examination hall than the gate was closed, shutting out all the late comers." This follows the proper "no sooner...than" structure (correlative conjunction) with inverted word order, where (C) acts as a participial phrase providing additional information -> correct
Hence, Option 1: (B), (A), (D), (C) -> The "no sooner...than" construction requires inversion (had + subject + past participle...than + clause). Part (C) functions as a present participle phrase that modifies the action of the gate being closed, providing the consequence of this action -> correct