In which reaction is a racemic mixture not obtained?

The rate-limiting step of an $S_N1$ reaction follows the sequence shown below. Based on the assumption that $R$ contains $3$ different groups,which statement is true?
$\mathop R\limits^{\delta \oplus } \,\mathop {Br}\limits^{\delta \Theta } \, \rightleftharpoons \,\mathop {\boxed{{R^ \oplus }Br^\Theta }}\limits_{(a)} \,\,\, \rightleftharpoons \,\mathop {\boxed{{R^ \oplus }}\,\boxed{Br^\Theta }\,}\limits_{(b)} \,\, \rightleftharpoons $ ${\boxed{{R^ \oplus }}}$ $ + $ $\mathop {\,\boxed{Br^\Theta }\,}\limits_{(c)} \,$

Which of the following is true about the given graphs $A$ and $B$?

Which of the following major product is not correct $:-$

In a nucleophilic substitution reaction,the order of halogens as incoming (attacking) nucleophiles is: $I^{-} > Br^{-} > Cl^{-}$. The order of halogens as departing (leaving) nucleophiles should be:

Which of the following statements is invalid?