Explain the stereochemistry of the products from `E2` dehalogenation with `I^(Θ)` of the following.
`a.` `(i)` Meso `-2-3-`dibromobutane and `(ii)` `S,S-2,3-` dibromo`-` butane.
`b.` `E2-` dehydrobromination of `(i)` `R,R-2,3-` dibromobutane and `(ii)` meso`-(R,S)-2,3-` debromobutane
`c.` From which conformation of bromocyclohexane in the `E2` dehydrobromination is best achieved.

Explanation

To explain the stereochemistry of the products from E2 dehalogenation with iodide ions of the given compounds, we will analyze each part step by step.

### Part a:
**(i) Meso-2,3-dibromobutane**

1. **Identify the Structure**: Meso-2,3-dibromobutane has two bromine atoms on adjacent carbon atoms (C-2 and C-3) and is symmetrical. The structure can be represented as:
```
CH3-CH(Br)-CH(Br)-CH3
...