According to the Constitution, in which of the following matters is the Centre empowered to give directions to the states with regard to the exercise of their executive power?
1. Construction and maintenance of means of communication declared to be of national or military importance.
2. Drawing up and execution of the specified schemes for the welfare of Scheduled Tribes in the state.
3. Measures to be taken for the protection of the railways within the state.
4. Devolution of financial powers to local governments to enable them to function as units of self-government.
Select the correct answer using the codes given below: