All given modifications belong to adventitious roots, except
A. Reproductive root of Asparagus
B. Storage roots of sweet potato
C. Conical roots of carrot
D. Prop roots of banyan tree

Hint: Roots are modified based on certain characters such as nutrients absorption, transport, support, respiration, food storage, etc. Root modifications perform two functions i.e. physiological and mechanical.

Complete answer:
Adventitious roots are those plant roots that form from any non-root tissue and they are produced during both normal development and in stress conditions such as flooding, wounding, etc. They usually arise from the stem, internodes, or leaves.
Reproductive roots of Asparagus- These are the type of storage roots i.e. those roots where adventitious roots become swollen for food storage. These swollen roots develop in clusters at the base of the stem.
Storage roots of sweet potato- In sweet potato, adventitious roots arise from the nodes of the running stem. These roots are also known as edible-root tubers.
Conical roots of carrot- Conical roots are modifications of tap root i.e. a main root that grows vertically downward and gives off small lateral roots sprouts. These roots are conical or cone in shape with a broad base and with tapers gradually at the apex.
Prop roots of a banyan tree- Prop roots are also known as columnar roots, these adventitious aerial roots arise from the horizontal aerial branches of the trees such as the banyan tree. They grow vertically downward and penetrate the soil and become thick and assume the shapes of pillars. They support spreading branches of the tree.

Hence, the correct answer is option (C).

Note: These taproots are very thick with many roots sprouting laterally and the main function of the taproot is to absorb water and minerals to the plant and these roots go deep in the ground.