Among the properties `(A)` reducing`(B)` oxidising `(C )` complexing the set of properties shown by `CN^(Θ)`ion towards metal species is .

Options

A. `B,C`
B. `A,B,C`
C. `C,A`
D. `A,B`

Explanation

To solve the question regarding the properties of the cyanide ion (CN⁻) towards metal species, we will analyze its behavior in terms of reducing, oxidizing, and complexing properties.

### Step-by-Step Solution:

1. **Understanding the Cyanide Ion (CN⁻)**:
- The cyanide ion has a negative charge and consists of a carbon atom triple-bonded to a nitrogen atom. This structure allows it to act as a ligand in coordination chemistry.

**Hint**: Recall the structure and charge of the cyanide ion to understand its chemical behavior.

2. **Complexing Property**:
- CN⁻ can act as a ligand, meaning it can form complexes with metal ions. For example, in the complex ion [Co(CN)₆]³⁻, cyanide acts as a bidentate ligand, coordinating with the metal ion.

**Hint**: Think about how ligands interact with metal ions to form coordination complexes.

3. **Reducing Property**:
- The cyanide ion can act as a reducing agent. This is because it can donate electrons to other species. For example, in certain reactions, CN⁻ can reduce metal ions from a higher oxidation state to a lower one.

**Hint**: Consider the electron donation process and how it relates to reduction.

4. **Oxidizing Property**:
- CN⁻ does not act as an oxidizing agent. An oxidizing agent typically accepts electrons, but due to its negative charge, CN⁻ does not have the capacity to accept electrons from other species.

**Hint**: Review the definition of oxidizing agents and their electron-accepting behavior.

5. **Conclusion**:
- Based on the analysis, the cyanide ion (CN⁻) primarily exhibits complexing and reducing properties, but it does not act as an oxidizing agent.

### Final Answer:
The set of properties shown by the CN⁻ ion towards metal species is **complexing and reducing**.