$ Protists are unicellular eukaryotes.
! Eukaryotes do not have a nucleoid.

Options

A. If both As and R are correct and R is correct explanation of As
B. If both As and R are correct but R is not correct explanation of As
C. If As is correct, R is wrong
D. If both As and R are wrong.

Answer

To solve the question regarding the statements about protists and eukaryotes, we will analyze both the assertion and the reason step by step.

### Step 1: Understand the Assertion
The assertion states that "Protists are unicellular eukaryotes."
- **Explanation**: Protists are indeed classified as eukaryotes, which means they have cells that contain a nucleus and organelles. Most protists are unicellular, meaning they consist of a single cell.

### Step 2: Understand the Reason
The reason states that "Eukaryotes do not have a nucleoid."
- **Explanation**: This statement is also correct. Eukaryotic cells have a defined nucleus enclosed by a nuclear membrane, whereas prokaryotic cells (like bacteria) have a nucleoid, which is a region where the DNA is located without a surrounding membrane.

### Step 3: Evaluate the Relationship Between Assertion and Reason
Now we need to determine if the reason correctly explains the assertion.
- **Analysis**: While both statements are true, the reason (that eukaryotes do not have a nucleoid) does not explain why protists are classified as unicellular eukaryotes. The classification of protists as unicellular is based on their cellular structure, not the presence or absence of a nucleoid.

### Step 4: Conclusion
Based on the analysis:
- The assertion is true: Protists are unicellular eukaryotes.
- The reason is true: Eukaryotes do not have a nucleoid.
- However, the reason does not provide the correct explanation for the assertion.

Thus, the final answer is: **Both assertion and reason are correct, but the reason is not the correct explanation of the assertion.**

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