**Core Concept**
The liver is a vital organ divided into lobes, with the right and left lobes being the primary divisions. Understanding the anatomy of the liver is crucial for various medical procedures and conditions. The liver's division is based on the hepatic veins, portal veins, and hepatic arteries that supply it.

**Why the Correct Answer is Right**
The liver is divided into two main lobes by the falciform ligament, which contains the left hepatic vein, and the inferior vena cava, which separates the right and left lobes. The falciform ligament is a fibrous structure that attaches the liver to the diaphragm and the anterior abdominal wall. It is a key anatomical landmark that helps in identifying the left lobe of the liver.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the falciform ligament is a fibrous structure that separates the left lobe from the rest of the liver, not the right and left lobes.
**Option B:** This option could be incorrect because the inferior vena cava does separate the right and left lobes, but it's not the primary landmark that divides the liver into two halves.
**Option C:** This option is incorrect because the gallbladder is attached to the underside of the liver and is not a structure that divides the liver into two halves.

**Clinical Pearl / High-Yield Fact**
One important point to remember is that the liver's division is not just anatomical but also functional. The left and right lobes have different blood supplies and drainages, which can be relevant in liver surgery or transplantation.

**Correct Answer: A.**