Reasonable nutrition refers to the complete variety, sufficient quantity and appropriate proportion of nutrients contained in the diet; Keep a balance with the needs of the body. A balanced diet is the core of reasonable nutrition. A healthy diet should be reasonable and balanced, with diversified foods, reasonable combination of meat and vegetables and comprehensive and reasonable nutrition. Rice mainly provides starch, and beef and tofu mainly provide protein. There are no fruits and vegetables in this recipe, which will lead to insufficient vitamin intake. Therefore, it is necessary to add fruits and vegetables, indicating that A meets the meaning of the question.

So choose: a