If the corpus callosum is severed, how might this affect the way we perceive the world?

The corpus callosum is a part of brain that lies above the thalamus and connects the two hemispheres of the brain. It maintain link of communication between two of them. Its function is to transfer neural messages in between right hemisphere and left hemisphere. The severed corpus callosum will act as having two brains in one body. Each part of the hemisphere will have its own perception, speech and thought. There is a possibility that the individual wears a pant due to the signals from one hemisphere and the other hemisphere of brain signals to down the pant. There is a lack of coordination in the functions performed if corpus callosum is severed.

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.