The correct option is D 1951
This amendment added special provision for the advancement of any specially and educationally backward classes or the Scheduled Castes and the Scheduled Tribes. To fully secure the constitutional validity of zamindari abolition laws and to place reasonable restriction on freedom of speech. A new constitutional device, called Schedule 9 introduced to protect laws that are contrary to the Constitutionally guaranteed fundamental rights. These laws encroach upon property rights, freedom of speech and equality before law.