Assertion (A). Monkey acts as a reservoir host for the parasite that causes African sleeping sickness
Reason (R ). Reservoir host lodges the infective stages of the parasite when primary host is not available

Options

A. A and R are true and R is the correct explanation of A
B. A and R are true and R is the correct explanation of A
C. A is true but R is false
D. A is false but R is true.

Answer

To solve the question regarding the assertion and reason about the reservoir host for the parasite causing African sleeping sickness, we can break it down into a step-by-step analysis:

**Step 1: Understand the Assertion**
- The assertion states that "Monkey acts as a reservoir host for the parasite that causes African sleeping sickness."
- African sleeping sickness is caused by the parasite Trypanosoma brucei.

**Step 2: Evaluate the Assertion**
- While monkeys can act as reservoir hosts for some parasites, they are not known to be a reservoir for Trypanosoma brucei.
- Instead, Trypanosoma brucei primarily infects humans and various wild and domestic animals, but not specifically monkeys as a reservoir host.
- Therefore, the assertion is **incorrect**.

**Step 3: Understand the Reason**
- The reason states that "Reservoir host lodges the infective stages of the parasite when the primary host is not available."
- A reservoir host is indeed a host that can harbor a pathogen and maintain its lifecycle, especially when the primary host (the host that typically gets infected) is not present.

**Step 4: Evaluate the Reason**
- The reason provided is accurate. A reservoir host does serve to lodge the infective stages of a parasite when the primary host is absent, allowing the pathogen to persist in the environment.
- Therefore, the reason is **correct**.

**Step 5: Conclusion**
- Since the assertion is incorrect and the reason is correct, the correct option for this question is that the assertion (A) is false, but the reason (R) is true.

### Final Answer:
- Assertion (A) is false, and Reason (R) is true.