**Core Concept**
The question is testing the knowledge of H2 receptor antagonists with additional anticholinesterase activity, a property that can influence their pharmacological profile and potential side effects.

**Why the Correct Answer is Right**
Pirenzepine is a selective M1 muscarinic receptor antagonist with some anticholinesterase activity, which is a unique property among H2 blockers. This dual action can modulate the balance of cholinergic and anticholinergic effects, affecting the drug's efficacy and safety profile. Pirenzepine's anticholinesterase activity may contribute to its potential therapeutic benefits in conditions like peptic ulcer disease, but it also increases the risk of central anticholinergic side effects.

**Why Each Wrong Option is Incorrect**
**Option A:** Ranitidine is a widely used H2 blocker, but it does not possess significant anticholinesterase activity. It primarily acts as a competitive antagonist of histamine H2 receptors.
**Option B:** Famotidine is another commonly used H2 blocker, but it lacks notable anticholinesterase properties. Its primary mechanism involves competitive inhibition of histamine H2 receptors.
**Option C:** Nizatidine is an H2 blocker that has some anticholinergic activity, but it does not possess significant anticholinesterase properties. Its primary action involves competitive inhibition of histamine H2 receptors.

**Clinical Pearl / High-Yield Fact**
Pirenzepine's unique combination of M1 muscarinic receptor antagonism and anticholinesterase activity makes it an interesting candidate for the treatment of peptic ulcer disease, but its central anticholinergic side effects must be carefully monitored.

**Correct Answer:** C. Nizatidine