## Core Concept
The question pertains to toxicology, specifically plant poisons, and the availability of specific antidotes. Understanding the management of plant poisonings, including the role of antidotes, is crucial for treating patients effectively.

## Why the Correct Answer is Right
The correct answer, **D. Atropine**, is a specific antidote for certain plant poisons, notably those that cause muscarinic effects due to their anticholinesterase activity, such as organophosphates and carbamates, but more directly related to plant toxins like physostigmine (from *Physostigma venenosum*). Atropine acts by competitively inhibiting the muscarinic acetylcholine receptors, counteracting the excessive acetylcholine caused by these poisons.

## Why Each Wrong Option is Incorrect
- **Option A:** Without the specific toxin mentioned, it's hard to directly address, but many plant toxins lack specific antidotes, relying on supportive care.
- **Option B:** Similarly, without specifics, it's challenging, but the implication is that these might not have targeted antidotes.
- **Option C:** This option also lacks specificity but suggests a lack of antidote.

## Clinical Pearl / High-Yield Fact
A key point to remember is that for many plant poisonings, management is primarily supportive, with a few notable exceptions like the use of **atropine and pralidoxime** for organophosphate poisoning. Atropine's role in counteracting muscarinic effects makes it a critical antidote in certain cases.

## Correct Answer: D. Atropine