Bonsoir,
1) a) "They" fait référence aux "Governments, regulators and media companies" (les gouvernements, les régulateurs et les entreprises)
b) "It" fait référence à "advertising" (la publicité)
2) La réponse correcte est "because they view it as a source of revenue"
3) According to Justin Lewis, advertising has different forms of power : doing the propaganda of the consumerist ideology, sharing feelings of happiness, fulfilment, security, popularity, pleasure ... through consumption etc.
Bonne chance !
