**Core Concept**
Chromosome identification in intersex cases is crucial for diagnosing and managing disorders of sex development. The rapid method of chromosome identification involves analyzing the sex chromosomes to determine the presence of any abnormalities.

**Why the Correct Answer is Right**
The correct answer involves using a rapid technique called Fluorescence In Situ Hybridization (FISH) to identify specific chromosomes. FISH is a molecular cytogenetic technique that uses fluorescent probes to detect and locate specific DNA sequences on chromosomes. In the context of intersex cases, FISH can be used to identify the presence of sex chromosomes, such as X and Y, and detect any abnormalities, such as translocations or deletions. This information is essential for diagnosing disorders of sex development and guiding further management.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specify a rapid method of chromosome identification. While karyotyping is a common technique for chromosome analysis, it is not necessarily rapid and may not be suitable for emergency situations.
**Option B:** This option is incorrect because it is not a specific technique for chromosome identification. PCR (Polymerase Chain Reaction) is a molecular biology technique used for amplifying DNA sequences, but it is not directly used for chromosome identification.
**Option C:** This option is incorrect because it is not a recognized technique for chromosome identification. While microarray analysis is a technique used for analyzing gene expression and copy number variations, it is not typically used for rapid chromosome identification.

**Clinical Pearl / High-Yield Fact**
A key point to remember is that FISH is a rapid and sensitive technique for identifying specific chromosomes, making it an essential tool in the diagnosis of intersex cases. This technique can provide critical information for guiding further management and ensuring accurate diagnosis.

**Correct Answer: C. FISH (Fluorescence In Situ Hybridization)**