Identify the correct statement related to substitution and elimination of alkyl halides?

The ability of a species to act as a good leaving group is a crucial factor in both substitution (SN1,SN2) and elimination (E1,E2) reactions. Good leaving groups are typically weak bases (conjugate bases of strong acids, such as (I−,Br−,Cl−,TsO−,H2O) that can stabilize the negative charge once they depart. The better the leaving group, the faster the reaction (either substitution or elimination) will proceed, as the carbon-leaving group bond must be broken in all four mechanisms.