The correct option is B Born
Homophones are words that have the same or similar pronunciations, but different meanings. 'Borne' and 'born' are homophones.
Options A and B:
'Born' means 'brought forth by birth', or 'coming into this world'.
It is relevant to the given sentence, as it means: the person 'Stalin' was brought into this world by poor parents.
'Borne' is the past tense of 'bear', and means 'to hold up or support'.
This word does not fit into the sentence in meaning.
Hence option B is correct and A is incorrect.
Options C and D are incorrect for the same: C cannot be correct because A is incorrect, and D cannot be correct because B is correct.