Which of the following is not a grain? fish, oatmeal, brown rice, whole wheat bread

The following foods are made from grains; Oatmeal, Brown Rice and Whole wheat bread except for Fish. Fish is a meat. The grain food group consists of foods that come from cultivated cereal crops. This means they are grown from plants. Fish is a living animal which is found in the seawater and is used as meat for human consumption.

Magnesium! this is found if caves usually