The correct option is A Toluene
The reactivity of compound towards electrophilic nitration depends on the electron density present on the compound. The higher the electron density, the more reactive will be the compound towards electrophilic nitration.
Here toluence is most reactive towards electrophilic nitration as the presence of methyl group induces electron donating effect which increases the electron density.
correct order of reactivity toward electrophilic nitration is
toluene>benzene>benzoic acid>nitrobenzene