Final answer:
Granitic rock is the dominant rock type in the continental crust of the Earth, which constitutes around 45% of the Earth's surface. Oceanic crust primarily consists of basalt rock. Subduction zones and seafloor spreading areas also primarily involve basalt, not granite.
Step-by-step explanation:
The granitic rock is the dominant type in the continental crust of the Earth. The Earth's crust consists of two main types of crust, namely, oceanic crust and continental crust. The oceanic crust, which covers 55% of the Earth's surface, is primarily composed of basalt rock. On the other hand, the continental crust, making up the remaining 45% of the surface, is overwhelmingly composed of a type of igneous silicate rock called granite.
At subduction zones and areas of seafloor spreading, the rock type that is most commonly found is basalt, not granite. When two tectonic plates converge at a subduction zone, one, often the oceanic plate, is thrust down into the mantle. This process does not typically involve granitic rock of the continental crust due to its thickness. Therefore, the correct answer is option C), granitic rock is the dominant rock type in the continental crust.
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