For the preparation of sodium thiosulphate by "Spring's reaction', the reactants used are

Options

A. `Na_(2)S+Na_(2)SO_(3)+CI_(2)`
B. `Na_(2)S+SO_(2)`
C. `Na_(2)S+Na_(2)SO_(3)+I_(2)`
D. `Na_(2)SO_(3)+S`

Explanation

To prepare sodium thiosulphate (Na2S2O3) using Spring's reaction, we follow these steps:

### Step-by-Step Solution:

1. **Identify the Reaction**: The first step is to understand what Spring's reaction is. It involves the reaction of sodium sulfide (Na2S) with iodine (I2).

2. **Write the Chemical Equation**: The balanced chemical equation for the reaction is:
\[ \text{Na}_2\text{S} + \text{I}_2 \rightarrow \text{Na}_2\text{S}_2\text{O}_3 + \text{NaI} \]
Here, sodium sulfide reacts with iodine to produce sodium thiosulphate and sodium iodide.

3. **Identify the Reactants**: From the chemical equation, we can identify the reactants used in the preparation of sodium thiosulphate:
- Sodium sulfide (Na2S)
- Iodine (I2)

4. **Final Product**: The final product of the reaction is sodium thiosulphate (Na2S2O3) and sodium iodide (NaI).

5. **Crystallization**: After the reaction, the sodium thiosulphate can be crystallized from the solution, typically forming the pentahydrate form (Na2S2O3·5H2O).

6. **Conclusion**: Thus, the reactants used for the preparation of sodium thiosulphate by Spring's reaction are sodium sulfide and iodine.

### Answer:
The reactants used are sodium sulfide (Na2S) and iodine (I2).