In collision theory of chemical reaction, \({\mathrm{Z}}_{\mathrm{AB}}\) represents [NEET 2020]

The collision frequency of reactants, A and B

Steric factor

The fraction of molecules with energies equal to \({\mathrm{E}}_{\mathrm{a}}\)

The fraction of molecules with energies greater than \({\mathrm{E}}_{\mathrm{a}}\)