**Core Concept**
The life cycle of filaria involves a complex series of developmental stages, including microfilariae, infective larvae, and adult worms. The parasite's life cycle is influenced by environmental factors, host immunity, and vector biology.

**Why the Correct Answer is Right**
The life cycle of filaria begins with the deposition of microfilariae in the skin by an infected mosquito. The microfilariae then penetrate the skin and mature into infective larvae, which are ingested by another mosquito during a blood meal. The infective larvae develop into sporozoites, which eventually form a new generation of microfilariae. This cycle is repeated continuously, with the parasite adapting to the host's immune response and environmental conditions. Key enzymes and pathways involved in this process include the development of microfilariae into infective larvae, which is influenced by the activity of chitinases and other enzymes that break down the cuticle.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incomplete and does not provide a viable explanation for the life cycle of filaria.
**Option B:** This option may be a distractor, but it is not a comprehensive explanation of the life cycle of filaria.
**Option C:** This option may be a partial explanation, but it lacks detail and does not accurately describe the complex series of developmental stages involved in the life cycle of filaria.

**Clinical Pearl / High-Yield Fact**
It is essential to note that the life cycle of filaria is influenced by environmental factors, such as temperature and humidity, as well as host immunity and vector biology. Understanding the life cycle of filaria is crucial for developing effective control measures and preventing the transmission of this disease.

**Correct Answer: D. The life cycle of filaria involves a complex series of developmental stages, including microfilariae, infective larvae, and adult worms.**