Amoebas prey upon algae in aquatic environments.

True

Explanation:

Amoeba are called amoeboid and are Eukaryotas (a one cell organisms known as unicellular) . The amoeba moves in a crawling fashion. Amoeba are shapeless engineer as the organism takes different shape.

Amoeba are tiny in a nature and are usually microscopic in nature . Amoeba  animals are found in small area of aquatic such as ponds , ditches and streams.

Amoeba feeds on various organisms like bacteria, algae , plant cells and microscopic protozoans . They devour this tiny particles of food by surrounding it with the pseudopods . They digest this food with the food vacuoles.  

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.