9. Dr. Wilson discovers a new chemical that he predicts will increase energy levels in hamsters. He designs an experiment to test his prediction
Dr. Wilson
the 12 hamsters into two equal groups. He gives one group of
hamsters the chemical but does not give the chemical to the other group. He keeps
everything else about the hamsters' living environment the same.
Over the next month, Dr. Wilson measures the time that the hamsters spend running on
their exercise wheels each day. He then calculates averages for these measurements,
which are shown in the table.
The data that Dr. Wilson collects during his experiement

the answer to your question is sperm

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.