The major buffer in blood is composed of the weak acid carbonic acid (H2CO3) and its conjugate base, bicarbonate ion (HCO3 - ). The normal pH of blood is 7.2-7.4, which is very far removed from the pKa value. The pH is kept in check by the lungs, which remove CO2 via exhalation, and by the kidneys, which excrete acid (H3O ) in the urine. People with impaired lung function are not able to exchange carbon dioxide efficiently between the lungs and air. The result is an increase in the amount of CO2 dissolved in the blood. How does this affe?

The increase in the amount of  carbon dioxide in in blood will lead to respiratory acidosis

Explanation:

Carbon dioxide in its normal level between  38 to 42 mm Hg plays vital roles in the human body like regulating the PH of the human blood, breathing regulation and other things. If the amount of carbon dioxide is high more than the range level, it will cause what is called respiratory acidosis.

Respiratory acidosis is a situation in cause by decrease in ventilation i.e Oxygen level leading to increase in carbon dioxide and drop in PH level of the blood.

c. earths continental crust is thicker than its lithosphere.

because, the lithosphere is the outermost layer of the earth/ 100 km thick and is defined by its machanical properties.the lithosphere contains oceanic and continental crust that varies in age and thickness across locations and geologic time. the lithosphere is the coolest layer of the earth in terms of temperature. the term lithosphere should not be confused with the use of "geosphere" which is used to indicate all of earth systems, including the atmosphere, hydrosphere   and biosphere. the surface of the earth can be divided into the continental crust and the oceanic crust.   the continental crust is made mostly of granite while the oceanic crust is made of basalt. the average thickness of the continental crust is 25 miles and the average thickness of the oceanic crust is 5 miles.   three types of rock, igneous, sedimentary, and metamorphic, make up the surface of the earth. that's why 3 option is preferable.