**Core Concept**
Adipocere formation is a process of decomposition where fatty tissues are converted into a wax-like substance. This process requires specific conditions to occur, including the presence of certain microorganisms and a humid environment.

**Why the Correct Answer is Right**
Adipocere formation typically occurs in moist environments, where bacteria such as Clostridium and Bacillus can break down the fatty acids in the body. These bacteria thrive in environments with high humidity (above 60%) and temperatures between 15°C and 30°C. The presence of oxygen also plays a crucial role in the formation of adipocere.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because adipocere formation does not require a dry environment. In fact, the opposite is true: a humid environment is necessary for the process to occur.

**Option B:** This option is incorrect because while temperature does play a role in decomposition, adipocere formation is not limited to a specific temperature range. It can occur within a wide range of temperatures.

**Option C:** This option is incorrect because while oxygen is necessary for some decomposition processes, adipocere formation is actually facilitated by the absence of oxygen. Anaerobic bacteria are responsible for breaking down the fatty acids in the body.

**Clinical Pearl / High-Yield Fact**
It's essential to note that adipocere formation is relatively rare in modern forensic pathology, as most bodies are discovered and processed relatively quickly. However, in cases where bodies are left in the environment for extended periods, adipocere formation can be a distinctive and important sign of decomposition.

**Correct Answer:** D.