**Core Concept**
The question is related to the nutritional content of sorghum, a type of cereal grain. Sorghum is known for its high nutritional value, including its protein, fiber, and mineral content. The specific nutrient in question is likely related to its potential to cause health issues if consumed in excess.

**Why the Correct Answer is Right**
Sorghum contains an excess of **cyanogenic glycosides**, which can release **cyanide**, a toxic substance, when ingested. This is particularly relevant in certain varieties of sorghum and under specific conditions. The presence of these compounds is a concern for human and animal health.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because while sorghum does contain various nutrients, the specific excess nutrient in question is not listed here.
**Option B:** Similarly, this option does not accurately identify the excess nutrient in sorghum.
**Option D:** This option is also incorrect as it does not correctly represent the excess nutrient found in sorghum.

**Clinical Pearl / High-Yield Fact**
It's crucial to note that proper processing of sorghum can reduce the levels of toxic compounds, making it safer for consumption. Awareness of the nutritional and potential toxic content of foods is vital for preventing health issues.

**Correct Answer:** C. Cyanogenic glycosides