Mountain climbers often use two different techniques to breathe at high altitudes: one is a rapid, shallow breathing method, and the other is a slower, deep breathing technique. It is observed that climbers using the rapid, shallow method frequently switch to the deep breathing method after several hours. One hypothesis is that rapid, shallow breathing is less effective for oxygen intake at high altitudes; another hypothesis is that muscle fatigue from rapid breathing necessitates the switch to deeper breaths.Which of the following, if observed in experiments with climbers at high altitudes, would support one of the two hypotheses and undermine the other?(A) Climbers who start with deep breathing and switch to rapid, shallow breathing report greater fatigue than those who do not switch techniques.
(B) Climbers using the rapid, shallow breathing method for an extended period of time show a decrease in blood oxygen levels over time, which improves after switching to deep breathing.
(C) Climbers who practice deep breathing techniques at lower altitudes find it easier to maintain this method when climbing at high altitudes.
(D) Experienced climbers tend to use deep breathing consistently, while less experienced climbers often start with rapid, shallow breathing.
(E) The frequency of climbers switching from rapid, shallow breathing to deep breathing is higher in extremely cold conditions.
Solution:Hypothesis 1 - Rapid, shallow breathing is less effective for oxygen intake at high altitudes.
Hypothesis 2 - Muscle fatigue from rapid breathing necessitates the switch to deeper breaths.
(A) Climbers who start with deep breathing and switch to rapid, shallow breathing report greater fatigue than those who do not switch techniques.
Explanation: This choice partly supports Hypothesis 2 but doesn't address anything about Hypothesis 1.
INCORRECT(B) Climbers using the rapid, shallow breathing method for an extended period of time show a decrease in blood oxygen levels over time, which improves after switching to deep breathing.
Explanation: This option directly supports the hypothesis 1 by showing that rapid breathing leads to decreased oxygen levels which improve with deep breathing. This also weakens the hypothesis 2 as it suggests that muscle fatigue is not the reason for switching the breathing technique rather it is to help increase the blood oxygen levels.
CORRECT(C) Climbers who practice deep breathing techniques at lower altitudes find it easier to maintain this method when climbing at high altitudes.
Explanation: This option offers a secondary explanation for why some climbers might prefer deep breathing but does not offer direct evidence for either hypothesis.
INCORRECT(D) Experienced climbers tend to use deep breathing consistently, while less experienced climbers often start with rapid, shallow breathing.
Explanation: This option talks about a general trend but doesn't offer any insight on supporting or undermining either hypothesis.
INCORRECT(E) The frequency of climbers switching from rapid, shallow breathing to deep breathing is higher in extremely cold conditions.
Explanation: This option talks about a factor causing the switch but doesn't offer any evidence for either hypothesis.
INCORRECTOption B is the right choice