**Core Concept**
Malaria is a vector-borne disease caused by Plasmodium parasites transmitted through the bite of infected Anopheles mosquitoes. Non-human reservoirs refer to the presence of a parasite in a host other than humans, which can potentially serve as a source of infection for vectors and humans.

**Why the Correct Answer is Right**
The correct answer is **D. Yaws**, which is a bacterial infection caused by Treponema pallidum subspecies pertenue. Unlike malaria, yaws does not have a non-human reservoir and is primarily transmitted through skin-to-skin contact with an infected individual. This is in contrast to malaria, which has various non-human reservoirs, including monkeys and other animals.

**Why Each Wrong Option is Incorrect**
**Option A:** Malaria has a non-human reservoir, including monkeys and other animals.
**Option B:** Plague has a non-human reservoir, including rodents and other mammals.
**Option C:** Leishmaniasis has a non-human reservoir, including dogs and other animals.

**Clinical Pearl / High-Yield Fact**
It is essential to recognize the non-human reservoirs of various diseases to understand the transmission dynamics and develop effective control measures.

**Correct Answer: D. Yaws**