MCQ
Choose the halogen which is most reactive towards $SN1$ reaction in the given compounds $(A, B, C , D)$
- A$A - Br _{(b)} ; B - I _{( b )} ; C - Br _{( b )} ; D - Br _{( b )}$
- ✓$A - Br _{( a )} ; BI _{( a )} ; C - Br _{( b )} ; D - Br _{( a )}$
- C$A - Br _{( b )} ; B - I _{( a )} ; C - Br _{( a )} ; D - Br _{( a )}$
- D$A - Br _{( b )} ; B - I _{( a )} ; C - Br _{( a )} ; D - Br _{( a )}$
