## **Core Concept**
The concept of an "ideal protein" refers to a protein that provides all essential amino acids in the optimal proportions required by the human body for growth and maintenance. Essential amino acids are those that cannot be synthesized by the human body and must be obtained through the diet.

## **Why the Correct Answer is Right**
Egg protein is considered an ideal protein because it contains all nine essential amino acids in a well-balanced ratio that matches the human body's needs. The essential amino acids include histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. Eggs are particularly noted for their high-quality protein, making them a standard reference point for measuring the protein quality of other foods.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is incorrect because while eggs do contain all essential amino acids, stating they are ideal simply because they have "all amino acids" overlooks the importance of the balanced ratio of these amino acids.
- **Option B:** This option is incorrect as it does not specify why eggs are considered ideal protein; having a "high protein content" is not unique to eggs and does not address the balance of amino acids.
- **Option C:** Although not provided, any option suggesting a reason that does not directly relate to the balanced profile of essential amino acids would be incorrect.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that the biological value (BV) of egg protein is 100, which is the highest among all foods. The BV is a measure of the proportion of absorbed protein from a food which becomes incorporated into the proteins of the organism's body. This makes eggs an excellent dietary source of protein for humans, especially for growth, repair, and maintenance of body tissues.

## **Correct Answer:** . High biological value.