Final answer:
Hollywood studios adopted the Production Code in 1934 mainly to avoid federal government regulation, preferring to self-regulate the content of their films.
Step-by-step explanation:
The real reason why Hollywood studios adopted the Production Code in 1934 was predominantly because the studios preferred self-regulation to federal government regulation (Option A). Amid growing public and governmental pressure concerning the content of films, including issues of morality and decency, the studios wished to avoid the potential of more restrictive regulations that could be imposed by the federal government. This move was a pre-emptive measure to maintain some level of autonomy over film content and to prevent external censorship beyond the control of the film industry itself.