When excess chlorine is used in electrophilic substitution of toluene, which of the following dichloroarenes are formed?

ortho and para

The methyl group in toluene is an ortho/para director, so when excess chlorine is used, the dichloroarenes that are formed will be ortho and para isomers. So the answer is (3).

Here is a diagram of the reaction:

The ortho isomer is the one where the chlorine atoms are on the same carbon atom as the methyl group, and the para isomer is the one where the chlorine atoms are on adjacent carbon atoms to the methyl group.

The meta isomer is not formed because the methyl group is an ortho/para director, and it does not activate the benzene ring at the meta position.