The hallmark of watershed development in the semi-arid regions of India is the

(a)

establishment of sheds on large scale, so that the rain water does not evaporate

(b)

undertaking of earthworks, soil conservation measures and tree plantation, so as to conserve soil moisture and recharge underground water

(c)

drilling deep tubewells so as to tap water at the rock-strata level

(d)

setting up a system of tanks by banking water from seasonal rivers