## Core Concept
The question revolves around the body's method for safely storing and transporting ammonia, a toxic substance, particularly in the context of nitrogen metabolism. Ammonia is a byproduct of amino acid catabolism and must be handled carefully by the body to prevent neurotoxicity.

## Why the Correct Answer is Right
The correct answer, glutamine, is a non-toxic form in which ammonia is transported in the bloodstream and stored. This process involves the condensation of ammonia with α-ketoglutarate to form glutamine, a reaction catalyzed by the enzyme **glutamine synthetase**. Glutamine serves as a reservoir for ammonia and can be converted back into ammonia in the kidneys for excretion as urea. This mechanism is crucial for ammonia detoxification.

## Why Each Wrong Option is Incorrect
- **Option A:** This option is blank and does not provide a viable alternative.
- **Option B:** This option is also blank and does not offer a valid choice.
- **Option C:** Similarly, this option is blank and lacks a relevant substance.
- **Option D:** This option too is blank and does not contribute a correct or incorrect substance for consideration.

## Clinical Pearl / High-Yield Fact
A key point to remember is that **glutamine** acts as a critical nitrogen transporter and reservoir, particularly from muscle to kidney, helping in ammonia detoxification. This process is vital in conditions where ammonia levels might rise, such as liver disease or severe muscle breakdown.

## Correct Answer Line
**Correct Answer: B. Glutamine**