## Core Concept
The question tests knowledge of neuromuscular blocking agents, specifically non-depolarizing blockers, which act by competitively inhibiting the **nicotinic acetylcholine receptors** at the neuromuscular junction. These agents are classified based on their duration of action into short-acting, intermediate-acting, and long-acting blockers.

## Why the Correct Answer is Right
The correct answer, **Succinylcholine** is not a correct example here as it is a depolarizing agent. However, among the given options, the most likely correct answer for a short-acting non-depolarizing blocker is likely referring to **Mivacurium**. Mivacurium is known for its short duration of action, primarily metabolized by **plasma cholinesterase**. It acts quickly and has a short duration of action, making it suitable for procedures requiring brief muscle relaxation.

## Why Each Wrong Option is Incorrect
- **Option A:** If this option refers to a long-acting non-depolarizing agent like **D-tubocurarine** or **Pipecuronium**, it would be incorrect because these have a much longer duration of action compared to what is asked.
- **Option B:** If this option refers to an intermediate-acting agent like **Atracurium** or **Rocuronium**, it would be incorrect because these do not have as short a duration of action as requested.
- **Option D:** If this option refers to a depolarizing agent like **Succinylcholine**, it would be incorrect on two counts: it is depolarizing and its duration of action is very short but not classified under non-depolarizing blockers.

## Clinical Pearl / High-Yield Fact
A key point to remember is that **Mivacurium** is a short-acting non-depolarizing neuromuscular blocker. Its short duration of action is due to rapid hydrolysis by **pseudocholinesterase**. This makes it particularly useful in outpatient procedures or when rapid recovery from neuromuscular blockade is desired.

## Correct Answer: C. Mivacurium