The Russian revolutionaries derived their ideology from the doctrines of .

The correct answer is Option 3: Marx and Engels.

The Russian Revolutionaries, particularly the Bolsheviks led by Lenin, based their fundamental political and economic philosophy on Marxism. This ideology was co-founded by Karl Marx and Friedrich Engels in works like The Communist Manifesto and Das Kapital. They provided the core theoretical framework regarding class struggle, the inevitable downfall of capitalism, and the establishment of a classless society.

• Why Option 3 is correct: Marx and Engels provided the original 19th-century doctrines that served as the "bible" for Russian revolutionaries. Without their foundational theories on historical materialism, the revolutionary movement would lack its ideological roots.
• Why other options are incorrect: While Lenin was a crucial practitioner who adapted these ideas to Russia (Marxism-Leninism), he was a follower and interpreter of the original doctrines of Marx and Engels. Stalin emerged much later as a successor, focusing on the consolidation of the Soviet state rather than the foundational revolutionary doctrine.