## **Core Concept**
Sorghum, a type of grain, is known for its nutritional content, which includes various amino acids, vitamins, and minerals. However, it is particularly noted for containing certain compounds that can affect its nutritional quality and utilization by humans and animals.

## **Why the Correct Answer is Right**
The correct answer, **C.**, points to the fact that sorghum contains an excess of a specific amino acid. Sorghum is known to be high in certain amino acids, and among these, **lysine** is often highlighted as being relatively low, but another amino acid, **proline**, and particularly **methionine** are not the standout features. However, sorghum is notably high in **leucine**, an essential amino acid. Leucine is a branched-chain amino acid important for protein synthesis and has various metabolic roles. The high leucine content in sorghum can sometimes interfere with the metabolism of other amino acids.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is incorrect because, while sorghum does contain various nutrients, it is not particularly known for an excess of the compound listed here.
- **Option B:** Similarly, this option does not accurately represent the nutrient for which sorghum is known to have an excess.
- **Option D:** This option is also incorrect as it does not correctly identify the compound that sorghum contains in excess.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that sorghum's high **leucine** content can have implications for its use in diets, particularly in certain populations or when used as a primary source of nutrition. This can affect protein quality and utilization.

## **Correct Answer:** .