> Is it the CEO? They are unlikely to know enough about French taxation.

That's besides the point. If you want to operate in a certain country, you need to - as a business - familiarize yourself with their laws.

The CEO is ultimately responsible for ensuring the company abides the law. If the CEO doesn't know enough about French taxation, that's not an excuse not to follow the rules: the CEO should then delegate the task to someone they trust, but ultimately it's their responsibility.