The mechanism of \(S _{ N } 1\) reaction is given as \(R - X \rightarrow R ^{\oplus} X ^{\ominus} \rightarrow R ^{\oplus} \| X ^{\ominus} \stackrel{ Y^\ominus }{\rightarrow} R - Y + X ^{\ominus}\)                      Ion pair       Solvent separated ion pair A student writes general characteristics based on the given mechanism as: \((a)\) The reaction is favoured by weak nucleophiles \((b)\) \(R^ \oplus\) would be easily formed if the substituents are bulky \((c)\) The reaction is accompained by recemization \((d)\) The reaction is favoured by non-polar solvents. Which observations are correct \(?\)

1. A \(b\) and \(d\)
2. B \(a, b\) and \(c\)
3. C \(a\) and \(c\)
4. D \(a\) and \(b\)