If you climb halfway up Mount Everest, you will likely experience low levels of oxygen in your blood. Which of the following statements correctly helps explain why? O a. Halfway up Mt. Everest, the fractional content of oxygen in the air is much lower than it is at sea level.

O b. Halfway up Mt. Everest, the solubility of oxygen in the blood is much higher than it is at sea level.

O c. Halfway up Mt. Everest, the total atmospheric pressure is higher than it is at sea level.

O d. Halfway up Mt. Everest, the partial pressure of oxygen is much lower than it is at sea level.

i believe the correct answer from the choices listed above is the first option. the scientists need to look at the   validity of data, claims, hypotheses, and observations before  developing an argument. they base their arguments on facts that are present and they make sure they have proofs. 

explanation:

i think the answer would be d

the endomembrane system i think

those characteristics are cellular organization, reproduction, metabolism, homeostasis, heredity, response to stimuli, growth and development, and adaptation through evolution. some things, such as a virus, demonstrate only a few of these characteristics and are, therefore, not alive