I believe it is carbon dioxide.
bthe mooningcorrect answer
Assuming your ‘is’ in your question is ‘if’, you’re answer is True.
Answer: Unrealistically optimistic
Explanation:The behavior shown by the people who don't show the conscious nature towards the risky condition and still have a hopeful mind tendency for the future are people with the unrealistic optimistic behavior .
These type of people don't think in negative way which shows that they are not pessimist natured but they don't react to the problematic situation with real solution rather being extremely hopeful in impossible manner which makes them unrealistic.
Answer:
True
Explanation: Chronic stress is the cause of this. You can develop depression and eating disorders from this kind of stress.