A balanced diet means that the proportion of various nutrients is appropriate and the collocation is reasonable, so that people can obtain comprehensive and balanced nutrition. The main nutrients needed by human body are: sugar, fat, protein, water, inorganic salts and vitamins. The millet porridge in this breakfast recipe mainly provides sugar, while fried tofu and stewed soybeans mainly provide protein, oil and inorganic salts. Lack of vegetables and fruits will lead to insufficient vitamin intake, so we should supplement vegetables and fruits. It can be seen.

Therefore, choose: B.