4. In what ways did Joseph Stalin maintain a strong dictatorship? (Select all that apply) * He reorganized the Soviet Union's economy through a series of "five year plans."

He ruthlessly expunged all social and political opponents.

He kept the people in constant fear of punishment through secret police and the gulag system.

He enacted violent purges of society that saw thousands disappear almost overnight.
He allowed all religions to practice freely in Soviet russiA