Some socialist leaders, such as Rammanohar Lohia, distanced themselves from the Congress and increased their criticism due to:

The Congress' declaration of a socialist pattern of society

The correct answer is Option 1 - The Congress' declaration of a socialist pattern of society

The socialists believed in the ideology of democratic socialism which distinguished them both from the Congress as well as from the Communists. They criticised the Congress for favouring capitalists and landlords and for ignoring the workers and the peasants. But the socialists faced a dilemma when in 1955 the Congress declared its goal to be the socialist pattern of society. Thus it became difficult for the socialists to present themselves as an effective alternative to the Congress. Some of them, led by Rammanohar Lohia, increased their distance from and criticism of the Congress party. Some others like Asoka Mehta advocated a limited cooperation with the Congress.