The answer is C. Hope I helped!
Answer: Negative
Explanation:
Although they can be used in a vaguely positive lighting, persistent, stubborn, and obstinate are negative connotation words.
Persistent - continuing firmly in a course of action in spite of difficulty or opposition
Stubborn - having or showing determination not to change one's attitude or position on something, usually in spite of good arguments or reasons to do so
Obstinate - stubbornly refusing to change one's opinion or chosen course of action despite attempts to persuade one to do so
To Stop the destruction of the earth's resourses
so you remember new words those words will increase your vocabulary getting more knowledge into that brain of yours