Challenges of nation building

Read the following passage and answer the questions below:
“In the history of nation-building only the Soviet experiment bears
comparison with the Indian. There too, a sense of unity had to be forged
between many diverse ethnic groups, religious, linguistic communities
and social classes. The scale – geographic as well as demographic
– was comparably massive. The raw material the state had to work with
was equally unpropitious: a people divided by faith and driven by debt
and disease.” — Ramachandra Guha
(a) List the commonalities that the author mentions between India
and Soviet Union and give one example for each of these from
India.
(b) The author does not talk about dissimilarities between the two
experiments. Can you mention two dissimilarities?
(c) In retrospect which of these two experiments worked better and
why?