Mycorrhiza is a type of symbiotic association that occurs between fungi and roots of the plant in which both are benefited. Mycorrhiza has many important roles in soil chemistry, plant nutrition, and some other fields. Basically this association takes place between roots of plants and fungi in which fungi supply minerals from the soil and plants provide food and shelter to the fungi and thus both are benefited.
Explanation: Mycorrhiza is a symbiotic relationship between a plant and a fungi. Nearly 80 percent of all plants with root systems participate in this mutualistic relationship. In mycorrhiza, the fungus forms a haustoria that penetrates the cell walls of the plant's roots. The fungus absorbs all the nutrients from the roots as they are transported to the plant. In return, the fungus gives the plant necessary chemicals and minerals that it cannot properly reach on its own.
For much of the last quarter century, the leading theory of the driving force behind tectonic plate motions envisaged large scale convection currents in the upper mantle, which can be transmitted through the asthenosphere. So letter C. is the Answer.
This is an example of Newton's second law that says that you will need more force to move an object of a lot of mass. F = m×a; F=Force= M= Mass×A= Acceleration
