Answer: C. independent
Explanation:
(A.) headstrong wouldn't make sense if the answer is supposed to be positive
(B.) Since connotation means something like a word involving its literal meaning, detached wouldn't really fit that...
(C.) Independent is a word that's literal to its primary meaning, and of course it's quite obvious how 'independent' is a positive word ✔️✔️
(D.) I'm not sure how to explain, but this one is 100% wrong
