**Core Concept**
Rubella infection, also known as German measles, is a viral illness that can be detected through various laboratory tests. The detection of rubella infection is crucial, especially in pregnant women and children, as it can lead to severe congenital anomalies if transmitted to the fetus.

**Why the Correct Answer is Right**
The correct answer is **IgM antibody detection**. This method involves testing for the presence of IgM antibodies against the rubella virus in the blood. IgM antibodies are the first line of defense against infections and are typically produced within 1-2 weeks of exposure to the virus. Detecting IgM antibodies against rubella indicates a current or recent infection. This method is particularly useful in children, as it can help diagnose rubella infection in those who are too young to report symptoms.

**Why Each Wrong Option is Incorrect**
* **Option A:** **Complement fixation test** is not a commonly used method for detecting rubella infection. This test is more relevant for detecting other infections, such as syphilis and typhoid fever.
* **Option B:** **Viral culture** is a method used to isolate and grow the rubella virus in the laboratory. However, it is not as sensitive as IgM antibody detection and requires specialized equipment and expertise.
* **Option C:** **Skin test** is not a recognized method for detecting rubella infection. Skin tests are typically used to diagnose tuberculosis and other conditions.

**Clinical Pearl / High-Yield Fact**
Remember that rubella infection during pregnancy can lead to congenital rubella syndrome (CRS), which is characterized by a range of birth defects, including heart defects, hearing loss, and intellectual disability.

**Correct Answer:** D.