1. A) please list the assumptions for a rational preference S over a set of alternatives X. B) Suppose X = R1, the 1st quadrant of R2, draw a graph to show the indifference curve for perfect substitutes. Draw another graph to show perfect complements. C) Suppose one of the good is a "bad", please draw the corresponding indif- ference curve. D) On your graph please show why monotonicity implies indifference curves cannot intersect each other and must be downward sloped