**Core Concept**
The administration of vaccines during pregnancy is a crucial aspect of maternal immunization, aiming to protect both the mother and the fetus from vaccine-preventable diseases. Tetanus vaccination is a key component of this strategy, particularly in regions with high tetanus neonatorum rates.

**Why the Correct Answer is Right**
Tetanus vaccination is recommended during pregnancy, specifically in the third trimester, to provide protection against tetanus infection in the newborn. This is crucial because tetanus neonatorum can lead to severe and often fatal consequences in newborns. The tetanus toxoid vaccine stimulates the production of antibodies that are transferred from the mother to the fetus, providing passive immunity to the newborn. This is achieved through the placenta, which allows the transfer of maternal antibodies to the fetus.

**Why Each Wrong Option is Incorrect**
**Option A:** Influenza vaccination is also recommended during pregnancy, but it is not the primary vaccine given for the purpose of tetanus protection.
**Option B:** Oral polio vaccine is not routinely administered during pregnancy, as the live, attenuated virus could potentially pose a risk to the fetus.
**Option D:** Rabies vaccination is not commonly given during pregnancy unless there is a specific indication, such as a known exposure to rabies.

**Clinical Pearl / High-Yield Fact**
It is essential to note that the Tdap vaccine (tetanus, diphtheria, and pertussis) is also recommended during pregnancy, typically in the late second or early third trimester, to provide protection against pertussis, a potentially life-threatening disease in newborns.

**✓ Correct Answer: C. Tetanus**