Horses have a herbivorous diet, meaning they primarily eat plant-based foods. The correct answer includes a variety of horse-friendly foods such as bran, chaff, hay, lucrin, sugarbeet, oats, carrots, and apples. These foods provide the necessary nutrients and fiber for a horse's overall health and digestion. Grass is also an essential part of a horse's diet, as it is their natural forage. Including a combination of these foods ensures that the horse receives a balanced diet.