Suppose Julia and Zach are the only consumers of milk. Julia's demand for milk is defined as Q^d_julia=12-3Pat prices below $4 and zero for prices above $4. Zach's demand for milk is defined as Q^d_josh⁼10-2Pat prices below $5 and zero for prices above $5. If the market price for milk is $5.50, market demand is

a.10b.1c.zerod.1.5