The amount of dissolved oxygen in water may decrease because of the

decrease in density of water

increase in plants in the water

decrease in temperature of water

increase in organic matter in the water

Option D

Explanation:

Increase in organic matter in the water will lead to production of microbes, algae, and all other  water species  by feeding  on increased organic matter. This organic matter will act as  food for the species living under the water.

With increased food supply, the population of water species will also increase which in turn will consume more and more dissolved oxygen from water thereby making it devoid of oxygen.

Hence, option D is correct

chemical because it warmed up which involves temperature and it bubbled which includes changing

mark me brainiest

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.