(A): Catanation ability of sulphur is observed in polysulphides
(R): A polysulphide with eight sulphur atoms is known Disulphide

Options

A. Both A & R are true, R is the correct explanation of A
B. Both A & R are true, R is not correct explanation of A
C. A is true, R is false
D. A is false, R is true

Answer

To solve the question, we need to analyze both the assertion and the reason provided.

### Step-by-Step Solution:

1. **Understanding Catenation Ability of Sulfur**:
- Catenation is the ability of an element to form chains or rings by bonding with itself. Sulfur is known for its ability to catenate, forming various polysulfides.
- Polysulfides are compounds containing chains of sulfur atoms.

2. **Assertion Analysis**:
- The assertion states that "Catenation ability of sulfur is observed in polysulfides."
- This statement is true because sulfur can form long chains of sulfur atoms, which are indeed polysulfides.

3. **Reason Analysis**:
- The reason states that "A polysulfide with eight sulfur atoms is known as disulfide."
- This statement is false. A disulfide specifically refers to a compound with two sulfur atoms (S-S bond), such as in compounds like dimethyl disulfide (CH3)2S2. A polysulfide with eight sulfur atoms is actually referred to as "octasulfide."

4. **Conclusion**:
- Since the assertion is true and the reason is false, we conclude that the correct relationship is that the assertion is true, but the reason is incorrect.

### Final Answer:
- The assertion is true, and the reason is false.