**Core Concept**
Frozen section is a histopathological technique used during surgical procedures to provide rapid diagnosis of tissue samples. This technique is essential in surgical oncology, trauma surgery, and other specialties where immediate diagnosis can influence the surgical approach.

**Why the Correct Answer is Right**
Frozen section is typically used for rapid examination of tissue samples to assess for malignancy, identify specific cell types, or confirm the presence of certain microorganisms. However, acid fast bacilli (AFB) are usually identified using specific staining techniques, such as the Ziehl-Neelsen stain, on formalin-fixed, paraffin-embedded tissue sections, which is not feasible with frozen section. The frozen section would not be able to accurately identify AFB due to the destruction of the mycolic acid, a key component of the AFB cell wall, during the freezing process.

**Why Each Wrong Option is Incorrect**
**Option A:** Enzyme - Frozen section can be used to identify the presence of certain enzymes, such as prostate-specific antigen (PSA) in prostate cancer, using immunohistochemical stains.

**Option B:** Intraop Histopathological examination - Frozen section is indeed used for intraoperative histopathological examination to guide surgical decisions, such as determining the extent of tumor resection or identifying the need for further surgical intervention.

**Option C:** Fat - Frozen section can be used to identify lipomas or other fat-containing lesions by examining the tissue under the microscope.

**Clinical Pearl / High-Yield Fact**
When performing frozen section, it's essential to use a validated protocol and to communicate clearly with the surgical team to ensure accurate diagnosis and timely surgical intervention.

**✓ Correct Answer: D. Acid fast bacilli**