**Question:** Transovarian transmission is seen in-

A. Fetal development
B. Parasitic infection
C. Viral infection
D. Nutritional deficiencies

**Core Concept:** Transovarian transmission refers to the process where a pathogen, usually a virus or bacteria, enters an oocyte (egg cell) during ovulation or fertilization, and then infects the developing embryo or fetus. This can lead to congenital infections or birth defects.

**Why the Correct Answer is Right:** C. Viral infection is the correct answer because transovarian transmission primarily involves viruses that can infect the female reproductive system, particularly the ovaries. Examples include human immunodeficiency virus (HIV) and human papillomavirus (HPV). These viruses can enter the oocytes and cause congenital infections or immunodeficiency in the offspring.

**Why Each Wrong Option is Incorrect:**

A. Fetal development (Transovarian transmission does not specifically involve fetal development, but rather the oocyte and early embryo/fetus).
B. Parasitic infection: While transovarian transmission can occur with parasites, the focus here is on viral infections, which is why this option is incorrect.
D. Nutritional deficiencies: Transovarian transmission is not related to nutritional deficiencies; rather, it is a mechanism of pathogen entry into the reproductive system and subsequent congenital infections.

**Clinical Pearl / High-Yield Fact:** Transovarian transmission is a crucial concept to understand while studying infectious diseases, particularly those affecting the reproductive system. Remember that the primary focus is on viral infections entering the oocyte, causing congenital infections, or immunodeficiency in the offspring. Understanding transovarian transmission helps in diagnosing and treating such infections in pregnant women and assessing the risk of congenital transmission to the fetus.