Why does earth contain such diverse life forms?

It is located in the sun's green zone where habitability was and still is possible, this allowed the earth to develop various types of life. With varying climates this supported adaptations which later morphed the flora and fauna of our home planet.

species are diverse there because they can become highly specialized - food availability is stable

the temperature doesn't change too much, and resources are fine-grained.

these are primary reasons for why life-forms are so diverse.

the man is bald so he has no hair to get wet

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.