Following question is based on the information given below: (i) 'R×S' means 'R is father of S' (ii) 'R-S' means 'R is sister of S' (iii) 'R+S' means 'R is mother of S' (iv) 'R÷S' means 'R is brother of S' In the expression A+B×C÷D how is C related to A ?