Four mixtures are given below. (i) Kidney beans and chick peas (ii) Pulses and rice (iii) Rice flakes and corn (iv) Potato wafers and biscuits Which of these can be separated by the method of winnowing? (a) (i) and (ii) (b) (ii) and (iii) (c) (i) and (iii) (iii) and (iv)