The correct arrangement for decreasing order of electrophilic substitution of

I)Toluene

II) Benzene

III)Phenol

IV) Chlorobenzene

When +I groups are present on benzene ring, they increase the reactivity of benzene towards electrophilic substitution while -I groups decrease the reactivity.

Among the given options, Toluene and Phenol have +I groups i.e., -CH₃ and -OH groups respectively.

Similarly, Chlorobenzene has -I group i.e., -Cl.

Hydrogen atom of Benzene has intermediate reactivity between +I groups and -I groups.

So, the decreasing order of reactivity towards electrophilic substitution is:

Phenol > Toluene > Benzene > Chlorobenzene.