A. clarity
B. precision
C. definiteness
D. specificity
obscurity : the state of being unknown, inconspicuous, or unimportant.
clarity : the quality of being easy to see or hear.
precision : the quality, condition, or fact of being exact and accurate.
definiteness : clearly defined or determined; not vague or general; fixed; precise; exact
specificity : the quality of belonging or relating uniquely to a particular subject.
Antonym of obscurity is clarity