**Core Concept**
Causing hurt by means of poison, with the intent to commit an offense, is a specific type of criminal act that falls under the Indian Penal Code (IPC). This concept involves the use of poison as a means to inflict harm, which is a critical aspect of forensic medicine in investigating and prosecuting such crimes.

**Why the Correct Answer is Right**
Section 328 of the IPC specifically deals with causing hurt by means of poison, with the intent to commit an offense. This intent is a crucial element, as it distinguishes this section from others that deal with causing hurt or death without the specific intent to commit an offense. The use of poison is a significant factor in this section, as it often involves a deliberate and premeditated act, which is a key aspect of forensic investigation. The specific intent to commit an offense is what sets this section apart from others that deal with causing harm or death due to negligence or accidental means.

**Why Each Wrong Option is Incorrect**
**Option A:** Section 326A of the IPC deals with voluntarily causing grievous hurt by use of acid, etc. This section is specific to the use of corrosive substances like acid, which is not the same as causing hurt by means of poison.

**Option B:** Section 326 of the IPC deals with voluntarily causing grievous hurt. This section does not specifically mention poison or the intent to commit an offense, making it a broader category than Section 328.

**Option C:** Section 327 of the IPC deals with voluntarily causing hurt to extort property or a valuable security, or to constrain to do anything which is illegal or which may facilitate the commission of an offense. This section does not specifically mention poison or the intent to commit an offense.

**Option D:** Section 329 of the IPC deals with voluntarily causing grievous hurt to extort property or a valuable security, or to constrain to do anything which is illegal or which may facilitate the commission of an offense. This section also does not specifically mention poison or the intent to commit an offense.

**Clinical Pearl / High-Yield Fact**
When investigating cases involving poisoning, forensic experts must carefully consider the intent behind the act, as well as the specific substances used, to determine the appropriate section of the IPC that applies.

**✓ Correct Answer: A. Sec. 328 IPC**