Select the correct statement about cardiac output.
a. Stroke volume increases if end diastolic volume decreases.
b. Decreased venous return will result in increased end diastolic volume.
c. A slow heart rate increases end diastolic volume, stroke volume and force of contraction.
d. If a semilunar valve were partially obstructed, the end systolic volume in the affected ventricle would be decreased.

Explanation:

Cardiac output:  The volume of blood the heart pumps via the circulatory system per minute is known as cardiac output.  

Stroke volume : The volume of blood ejected by the left ventricle in one contraction is called or known as stroke volume and it  with  heart rate  defines the cardiac output.

Cardiac output, is :  A slow heart rate increases end diastolic volume, stroke volume, and force of contraction.

it's c. (to reduce the greenhouse effect/carbon gasses)

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.