Assume that Rajesh Singh’s income increased from $20000 per year to $30000 per year, and his demand for "store-brand" bread decreased from 80 loaves to 40 loaves per year. Which of the following most accurately describes Singh’s income elasticity for store-brand bread（）
A. Income elasticity is +1.00 and store-brand bread is a complimentary good.
B. Income elasticity is -0.60 and store-brand bread is an inferior good.
C. Income elasticity is -1.67 and store-brand bread is an inferior good.
