The answer is c. they should last 20 to 30 minutes.. for most people, thats a whole workout lol
Hello there! Your answer to your question would be that during stressful situations our bodies become more relaxed and thus makes are breathing becomes deeper but it affects it during stressful situations because our bodies tends to tense up and it becomes shallow with less oxygen is coming in you could say and also less carbon dioxide is being pumped out...
Hope this helps :)