Right Answer is:
When an indefinite pronoun is used and if the possession of indefinite pronoun need to be shown and one person need to be excluded then “else” is used after it and that “else” takes the apostrophe on it.
1. I follow your suggestion and nobody else’s.
2. I follow your suggestion and nobody else’s suggestion.
No body’s suggestion except yours. And for that exception “else’s” is used.
3. Nobody’s suggestion matters to me.
“Nobody’s”, without any exception, thus no “else’s” is required.
In the given sentence “the black people” need to be excluded thus “else’s” should be used.
Hence, option B is the correct answer.