Find the missing sentence out of the options provided that fits to form a meaningful paragraph.
Facebook has uncovered and removed dozens of pages, accounts and groups linked to Iran that the firm says coordinated "inauthentic behaviour", targeting people in the US and UK.________________________________________________________.The social network revealed that it uncovered the activity a week ago.
The company said it had identified 82 pages, groups and accounts that were coordinating inauthentic behaviour on Facebook and Instagram in violation of the platform's policies.
While the earliest signs of the activity date to June 2016, Facebook said much of the activity occurred over the last year.
The BBC asked the company how many people had seen the posts and pictures shared on the fake accounts, or clicked "attending" on the fake events. Facebook said it was not yet sure.
The affected posts focused on divisive topics such as race relations, opposition to President Donald Trump and immigration, it said.