From what I can see here, it looks like there is more than one answer but if you only need one answer, then the best bet would be letter C. Except for Lonnie, everyone in the family eats meat. As said earlier, complex sentences have one independent clause and one dependent. The independent clause is "Everyone in the family eats meat while the dependent clause here would be "Except for Lonnie" since that clause cannot stand on its own.
