**Core Concept**
The HPV (Human Papillomavirus) vaccine is a type of prophylactic vaccine designed to prevent infections caused by various strains of HPV, which can lead to cervical cancer and other anogenital cancers. The vaccine works by inducing immunity against specific HPV types, thereby preventing the development of associated diseases.

**Why the Correct Answer is Right**
The correct answer is D. Both bivalent and Quadrivalent because there are two types of HPV vaccines available: Cervarix (bivalent) and Gardasil (quadrivalent). Cervarix protects against HPV types 16 and 18, which are responsible for approximately 70% of cervical cancer cases, while Gardasil protects against HPV types 6, 11, 16, and 18. The bivalent vaccine provides protection against two HPV types, whereas the quadrivalent vaccine provides protection against four HPV types.

**Why Each Wrong Option is Incorrect**
**Option A:** The HPV vaccine is not monovalent, as it targets multiple HPV types, not a single type.
**Option B:** While Cervarix is indeed a bivalent vaccine, stating that the HPV vaccine is only bivalent is incorrect, as Gardasil is also available and quadrivalent.

**Clinical Pearl / High-Yield Fact**
It's essential for pediatricians and healthcare providers to be aware of the different types of HPV vaccines available and to choose the most appropriate vaccine based on the patient's age, risk factors, and medical history.

**✓ Correct Answer: D. Both bivalent and Quadrivalent**