Answer:
The lady sings quite nicely, doesn't she?
Explanation:
This is an example of a question tag because it repeats the same question that it asks at the beginning of the sentence as it does at the end.
I believe the sentence that contains no errors in capitalization is B.
In sentence A, French and Spanish should be capitalized.
In sentence C, Korean should be capitalized.
In sentence D, Hanukkah should be capitalized.