An observation is
a. a possible explanation for events using prior knowledge
b. always quantitative
c. made using any of the five senses
d. always qualitative

The correct answer for the blank is -

c. made using any of the five senses.

Explanation:

Observation can be described as a process of closely monitoring or observing a particular situation with the help of any of the five senses (that are eyes, nose, ears, taste, and skin). It enables a person acquire some information of the incidence or situation or person.

For instance, a person observed an accident that occured on the roadside when a car was hit by another car behind it. In this case, the person used his eyes in observing the scene.

Thus, option c) is the right 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.

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