Natural resources are classified as renewable and nonrenewable. What is the difference between the two? whether or not the resource exists in nature
whether or not the resource can be replaced
whether or not the resource dwindles in supply
whether or not the resource is useful to humans

The difference between a renewable and a non-renewable natural resource is whether or not the resource can be replaced.

Explanation:

Natural resources are those useful for human beings and for that reason are consumed by them.

Renewable natural resources —such as water, plants and trees or solar energy— are usually renewed at a rate greater than or equal to their consumption, so they are not depleted.

A non-renewable natural resource, such as petroleum, usually has a limited existence, or its renewal speed is very slow, so its consumption can decrease its quantity or deplete it.

The difference between renewable and non-renewable resources is in their long-term availability or depletion.

Other options are not correct because:

the animal that would be cutest if scaled down to the size of a cat? elephant

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.