How does earthworm helps the soil ?

Question

$\begin{array}{1 1} (a)\; \text{they help in providing nutrients and water to the soil} \\ (b)\; \text{improves soil porosity, creating channels that enhance the processes of aeration and drainage} \\ (c)\; \text{they help in producing high yields} \\ (d)\; \text{they help in crop rotation process and provide food for the soil} \end{array}$