By Daniel Kline The fast-food chain has struggled to serve one large audience and it’s trying again. McDonald’s (MCD) – Get McDonald’s Corporation Report struggles with offering healthy choices. It has offered them throughout the years with a variety of salads being introduced, not selling well, and quietly falling off the menu. McSalad Shakers that it debuted in 2000, for example, offered three different salads served in a cup that customers were apparently supposed to shake, but they never made much of a mark before being replaced in 2003 by McDonald’s Premium Salads, which also failed. Ther…