In: Economics
Answer: B) Leontief
Engel curve is a straight line: m = p1x1/a. The consumer has homothetic preferences, if the demand for good goes up by the same proportion as income.Thus perfect substitutes, perfect complements and Cobb-Douglas are homothetic preferences.
In case of quasi-linear preferences, income effect for x1 is zero. Engel curve is a vertical straight line