10 Which of these preferences does not represent a preferenc

10. Which of these preferences does not represent a preference ordering of per fect substitutes? (a) x2 + 3x + 3y + 2xy + y2 (c) x2 + 3xyy2 (d) They are all perfect substitues. (e) More than one of the above

Option (b) i.e min(x+y ; x² + y² + 2xy) does not represent a preference ordering of perfect substitutes. It represents the preference ordering of perfect complements.