(i) hold water for irrigation

(ii) hold water and prevent soil erosion

(iii) recharge groundwater

(iv) hold water permanently

(a) (i) and (iv)

(b) (ii) and (iii)

(c) (iii) and (iv)

(d) (ii) and (iv)

Correct option – ( b )

Explanation – check dams are small dams made of rocks , rock bags or sand bags . They are placed perpendicular to the flow of water Soil erosion is prevented by check dams and it also increases the ground water level . Also used to control the velocity of water ,