## **Core Concept**
The question tests the understanding of active and passive immunity, specifically when they can or cannot be administered together. Active immunity involves the production of antibodies by the individual's immune system, typically through vaccination, while passive immunity involves the direct administration of antibodies. The key concept here is that passive immunity can interfere with active immunity if given simultaneously.

## **Why the Correct Answer is Right**
The correct answer, Hepatitis B, is a situation where active and passive immunity can indeed be given together. For example, in cases of newborns to hepatitis B-positive mothers, administering hepatitis B immune globulin (HBIG) provides immediate, passive immunity, while the hepatitis B vaccine provides active immunity. This combined approach is a recommended strategy for preventing perinatal transmission of hepatitis B.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is not provided, but typically, situations involving immediate protection against infections where passive immunity could be beneficial would be considered.
- **Option B:** Similarly, without specifics, we assume other vaccines or conditions might not allow for simultaneous administration due to interference with immune responses.
- **Option D:** Rabies immunoglobulin (for immediate protection) and the rabies vaccine (for long-term immunity) are given together but in a specific manner (part of the dose infiltrated into the wound and the rest intramuscularly), indicating a scenario where they can be given together effectively.

## **Clinical Pearl / High-Yield Fact**
A critical point to remember is that when administering tetanus immunoglobulin (TIG) for immediate protection against tetanus, it should not be mixed in the same syringe as tetanus toxoid (the vaccine) and should ideally be given on the opposite side of the body. This is because tetanus toxoid induces active immunity, and mixing or giving it too closely with TIG could potentially interfere with the immune response to the vaccine.

## **Correct Answer:** B. Tetanus.