**Core Concept**
Organophosphorous compounds are a class of cholinesterase inhibitors that exert their toxic effects by binding to the enzyme acetylcholinesterase (AChE), preventing the breakdown of acetylcholine (ACh) in the nervous system. This leads to an accumulation of ACh in the synapse, resulting in overstimulation of cholinergic receptors.

**Why the Correct Answer is Right**
The binding site of organophosphorous compounds is the active site of acetylcholinesterase, where the enzyme normally catalyzes the hydrolysis of acetylcholine into choline and acetic acid. Organophosphorous compounds, such as sarin and tabun, covalently bind to the serine residue at the active site of AChE, thereby inhibiting its activity. This inhibition of AChE leads to an accumulation of ACh in the synapse, resulting in overstimulation of cholinergic receptors and the characteristic symptoms of organophosphorous poisoning, including muscle weakness, paralysis, and respiratory failure.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it does not specify the target of organophosphorous compounds. While they do affect the nervous system, their primary mechanism of action is through inhibition of acetylcholinesterase, not through other means.
* **Option B:** This option is incorrect because it is too vague and does not accurately describe the binding site of organophosphorous compounds. While the nervous system is affected by these compounds, the specific target is the acetylcholinesterase enzyme.
* **Option C:** This option is incorrect because it is not a specific enough description of the binding site of organophosphorous compounds. While the active site of acetylcholinesterase is indeed the target of these compounds, this option does not provide enough detail to be considered correct.

**Clinical Pearl / High-Yield Fact**
The use of pralidoxime (2-PAM) as an antidote for organophosphorous poisoning is based on its ability to reactivate acetylcholinesterase by cleaving the covalent bond between the phosphorus moiety of the organophosphorous compound and the serine residue at the active site of the enzyme.

**Correct Answer:** C. Active site of acetylcholinesterase