What is the primary composition of the majority of soybean seed?

The primary composition of the majority of soybean seed is oil. Soybeans are known for their high oil content, which typically makes up about 18-20% of the seed's weight. This oil is predominantly made up of unsaturated fats, which are considered healthier fats compared to saturated fats. In addition to oil, soybeans contain significant amounts of protein, approximately 36-40% of the seed's weight, which makes them an important source of protein in animal feeds and plant-based protein products. However, the focus of the question is on composition by weight, and the notable characteristic of soybeans is their oil content, thus making it the correct answer. Other components such as carbohydrates and water are present but do not comprise the majority of the seed's weight compared to oil.