Final answer:
The experiment found that college students were less stressed when they were informed about increased carbon dioxide trials, which allowed them to prepare mentally and manage their responses. So the correct answer is option (A).
Step-by-step explanation:
In the experiment where college students breathed air with increased amounts of carbon dioxide through a mask, the students found it much less stressful. Option b) were told which trial would contain an increased amount of carbon dioxide is correct. This is likely because the anticipation and mental preparation for the event of increased carbon dioxide inhalation can reduce anxiety and stress associated with uncertainty.
Understanding the effects of carbon dioxide on the body, it is clear that homeostasis and the regulation of respiratory activity are crucial. Carbon dioxide levels are closely monitored by the body and can influence respiratory rates. Sudden increases in carbon dioxide can lead to discomfort and panic, while predictable and informed scenarios allow individuals to manage their responses more effectively.