**Core Concept**
The question is testing the understanding of the life cycle of Plasmodium species, specifically the erythrocytic schizogony phase. This phase is a critical part of the malaria parasite's life cycle, where it undergoes asexual reproduction within the red blood cells of the host.

**Why the Correct Answer is Right**
During erythrocytic schizogony, the Plasmodium parasite undergoes a process called schizogony, where it multiplies and forms multiple merozoites. These merozoites are the products of this asexual reproduction and will go on to infect new red blood cells. The correct answer is the substance that is liberated during this phase, which is essential for the continuation of the parasite's life cycle.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not relate to the products of erythrocytic schizogony.
**Option B:** This option is also incorrect because it is not directly related to the process of schizogony.
**Option C:** This option is incorrect because it refers to the process of sporogony, which occurs in the mosquito vector.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that the erythrocytic schizogony phase is responsible for the majority of the clinical symptoms of malaria, including fever, chills, and anemia. Understanding the life cycle of the parasite is crucial for the development of effective treatment and prevention strategies.

**Correct Answer: C. Merozoites. Merozoites are liberated during erythrocytic schizogony of Plasmodium.**