Suppose the income elasticity for iPads is equal to 2 then this means that:_______ 
 a. if income increases by 2%, then the demand for iPads will decrease by 1%. 
 b. if income increases by $1 then the demand for iPads will increase by 2%. 
 c. if income increases by 1%, then the demand for iPads will increase by 2%. 
 d. if income increases by 1%, then the demand for iPads will decrease by 2%.