The correct option is
A Tuberous and fasciculated
The dahlia is a dicotyledon plant nd in Dahlia, the roots are fasciculated tuberous roots because the fibrous root system of the plant stores food in them for perennation converting them into a tuft of tubers. The roots are so independent that you can reproduce a daughter plant by cutting away a portion of the roots of an adult plant in a process called division.So, the correct option is (D)