Which style of leadership would be most effective in the following situation? anthony, pedro, angie, and emma have just been assigned a group project in their english class. they need to choose a book, come up with a specific project about it, and divide the work authoritarian laissez-faire democratic

I believe the best style of leadership here would be democratic.
All of them should decide by vote who they want their leader to be, which is what happens in democracy. Given that they all need to work together, it's best for them to decide together on the book, specific projects, and the division of their work, and the best option for them would be a democracy.
Authoritarian style would mean the leader will impose on them whatever he or she wants; laissez-faire would mean they 'employees' decide without really taking into account their leader, which shouldn't be done in this case.