Correct option is A
Active voice: The subject performs the action of the verb.
Passive voice: The subject receives the action of the verb.
Explanation:
Tense: Past continuous
Active: were offloading → Passive: were being offloaded
Object (the fish) becomes the subject of the passive form.
Other options are grammatically incorrect or illogical.
Example: The workers were offloading the goods → The goods were being offloaded by the workers.