Hint: The root is the part of the plant which is present below the ground level and forms the underground system. Roots serve to withdraw water and other important nutrients from the soil and it is transported to other parts of the plant. It also serves other functions such as storage of food, anchorage etc.
The root comprises the underground part of the plant. They are responsible for the absorption of water and important minerals that are present in the soil. It also provides an anchorage to the plant and helps to keep it upright.
In some cases, the roots undergo certain specific and specialized changes that are utilized by the plants in the existing environmental conditions. Root modifications involve everlasting and stable changes that are devoted to perform specific kinds of functions. In most of the conditions, the modifications that take place in the roots perform two important functions such as physiological and mechanical functions. The roots are used as anchorage, as support, for food storage and also for reproduction.
The root modification taking place in the roots are mostly incorporated in the form of permanent structural changes. The permanent change in the structure induced by drastic modifications enables the plant to resist and adapt to the environment. The root modification cannot be temporary as otherwise it wouldn’t allow it to perform a specific function always. In certain plants, the roots are altered to extract water and minerals from the land into various parts of the plant. They aid in providing support, storing food and respiration.
Therefore, the correct option is option C.
Overground aerial roots generate structural support typically. For food storage, storage roots (e.g. taproots and tuberous roots) are modified. In several different types of plants, aerial roots provide various functions depending on where the plant is located. For example, the corn and sugarcane stems have roots supporting from the lower nodes of the stem. Those roots are known as stilt. They are most frequently found in monocots, bushes and small trees. They go down and penetrate the ground obliquely. A modified adventitious root is observed in sweet potato.
Roots are modified to perform specific functions other than their normal functions which enables the plant to adapt better into the environment into different forms. These changes are known as root modification. The root change or modification occurs when there are structural modifications that are permanent in nature. In those cases, the structure of the root system permanently changes.