**Core Concept**
In forensic medicine, putrefaction refers to the decomposition of organic tissues after death, with different organs decomposing at varying rates due to their composition, blood supply, and microbial exposure. The sequence of putrefaction is influenced by the body's anatomy and the presence of fluids or secretions.

**Why the Correct Answer is Right**
The uterus, being a hollow organ with rich vascular supply and a high moisture content, retains putrefactive bacteria and secretions for a prolonged period. After death, the uterus remains relatively intact and is often the last organ to undergo significant putrefaction due to its position and the presence of retained menstrual or uterine contents. This makes it the final site of decomposition in females, especially in post-mortem investigations.

**Why Each Wrong Option is Incorrect**
Option A: The liver is highly vascular and rich in blood, making it one of the first organs to putrefy due to rapid bacterial colonization and high nutrient availability.
Option C: The brain, though initially protected, decomposes early due to high protein content and exposure to air and microbes.
Option D: The breast lacks significant blood flow and is mostly fatty tissue, which slows decomposition but does not follow the sequence of putrefaction in a predictable or last-order manner.

**Clinical Pearl / High-Yield Fact**
In forensic autopsies, the uterus is often the last organ to show signs of putrefaction in females, especially in cases where menstrual or uterine secretions are present. This is a key point in determining the time since death and gender in post-mortem examinations.

✓ Correct Answer: B. Uterus