What is the ruling on eating McDonald's and its sandwiches in America, given the ignorance of the method of slaughter and the one who performed it?

The basic ruling is that it is permissible to eat meat in American restaurants, given that America is a Christian country, provided it is known that the meat comes from permissible animals slaughtered according to Islamic law. Otherwise, it is not permissible to eat from it. However, it is advised to completely avoid eating from such restaurants due to the prevalence of unlawful slaughter and because those performing the slaughter are often Buddhists or irreligious.