Dominance and communication are
a. two ways that primates maintain group cohesion
b. not present in prosimians
c. completely innate
d. are the product of a solitary lifestyle

Option (a).

Explanation:

The primates shows well developed social behavior and easily distinguishable on the basis of social groups. The social organization in primates help them to show dominant behavior in society and helps them to protect from their enemies.

The dominance character of the primates makes them superior in their social groups. Communication among primates helps them to develop the social behavior. The cohesion is the proximity and bond strength among the individuals. The dominace and communication plays important role in the cohesion of pimates.

Thus, the correct answer is option (a).

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.