Extrusive igneous rocks cool and solidify quicker than intrusive igneous rocks. They are formed by the cooling of molten magma on the earth's surface. The magma, which is brought to the surface through fissures or volcanic eruptions, solidifies at a faster rate.
The answer is: [A]: simple.
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The sentence given:
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"<span>South Africa is the wealthiest and most powerful country of the region."
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is a simple sentence.</span>
