Final answer:
The Dukhobors were a sect of Russian origin known for their pacifism and communal living, falling under the category of the Old Believer sect.
Step-by-step explanation:
The Dukhobors were a religious group of Russian origin. Specifically, they were a sect that split from the Russian Orthodox Church in the 18th century, known for their pacifism and communal living. They fall under answer choice d: Old Believer sect. The Dukhobors emigrated in large numbers to Canada in the late 19th and early 20th centuries to escape religious persecution in Russia.