Which of these scientists was a contemporary and collaborator with charles darwin?
a. aristotle
b. alfred russel wallace
c. james watson
d. lamarck

The correct option is option B- Alfred Russel Wallace.

Explanation:

Alfred Russel Wallace was a British naturalist who worked with Darwin and helped him in establishing his theory of natural selection.

Wallace supplied birds to Darwin for his studies and even sent his theory to Darwin in 1858 which almost was the exact copy of the theory of Darwin.

Their relationship is considered one of the most important scientific relationship in the history of science where Wallace supported and admired "On the origin of species" and Darwin appreciated Wallace as the man who truly understood the theory of natural selection.

Thus, option B- Alfred Russel Wallace is the correct answer.

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.