**Core Concept**
The tuberculin test, also known as the Mantoux test, is a diagnostic tool used to assess latent tuberculosis infection. It involves injecting a small amount of purified protein derivative (PPD) into the skin, and the resulting skin reaction is measured to determine the presence of infection.

**Why the Correct Answer is Right**
The tuberculin test relies on the principle of delayed-type hypersensitivity, where a previously sensitized individual mounts an immune response to the PPD, leading to inflammation and a skin reaction. This reaction is mediated by T-cell activation and the release of cytokines, particularly interferon-gamma. The size of the skin reaction is directly related to the intensity of the immune response, with larger reactions indicating a more significant immune response.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the tuberculin test does not measure the presence of antibodies, but rather the cell-mediated immune response to PPD.
**Option B:** This option is incorrect because the tuberculin test does not involve the administration of live bacteria, but rather a purified protein derivative.
**Option C:** This option is incorrect because the tuberculin test is not used to diagnose active tuberculosis, but rather to detect latent infection.

**Clinical Pearl / High-Yield Fact**
A positive tuberculin test result indicates that the individual has been exposed to Mycobacterium tuberculosis at some point in their lifetime, but it does not differentiate between latent and active infection. A negative result does not rule out the possibility of infection, especially in individuals with compromised immune systems.

**Correct Answer:** D