**Core Concept**
Post-exposure prophylaxis (PEP) involves administering vaccines or immunoglobulins to prevent disease after exposure to a pathogen. Active immunity is achieved through vaccination, while passive immunity is provided by immunoglobulins.

**Why the Correct Answer is Right**
The correct answer is related to the type of exposure and the appropriate prophylactic measure. For most exposures, such as rabies or hepatitis B, both active (vaccine) and passive (immunoglobulins) immunity can be given together to provide immediate and long-term protection.

**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because for certain exposures, both active and passive immunity are recommended together.
**Option B:** Incorrect as it doesn't apply to the general principle of post-exposure prophylaxis.
**Option C:** Incorrect because it is not the exception to the rule of giving active and passive immunity together.

**Clinical Pearl / High-Yield Fact**
A key point to remember is that the choice between active or passive immunity, or both, depends on the disease, the timing of the exposure, and the individual's immune status.

**Correct Answer:** D. Rabies