Ape Do Good Screen Printing pecialize in creen printing t-hirt in San Francico, California. It ell it mot popular template for US$10 and ha a marginal cot, including a blank t-hirt and the printing, of US$6. Ape Do Good Screen Printing recently ran a difference-in-difference experiment and determined the demand elaticity i -5. Should Ape Do Good Screen Printing raie or lower price? What i the optimal price?