40. in the igneous rock chart, igneous rocks are classified primarily on the basis of a hardness b. texture and mineralogy c. mode of occurrence d. none of these

The correct option is: b. texture and mineralogy                    

Explanation:

Igneous rocks, also known as the magmatic rocks, is one of three main types of rocks that is formed by the solidification of magma, with or without the process of crystallization. These rocks are mainly found in the oceanic crust, basins, land surface and shields.

The igneous rocks are primarily classified on the basis of texture and composition or mineralogy.

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my answer has to be at least 20 characters so here are the rest of the characters lol

heat released by collision processes during accretion, and heat from decay of radioactive elements

explanation: