36. According to ES ( pp. 134 - 135), which of the following are essential characteristics of all multi - sided platform businesses ? 1 . The platform requires government support to be viable . 2 . Different groups of users benefit from connecting with each other ." 3 . An intermediary helps groups connect with each other by setting up a platform . A . I only* B. I and 2 C . 2 and 3 D. 1 , 2 , and 3 37 . According to ES ( pp. 136 and 140 ), payment card systems are two -sided platforms in which the two sides are A. consumers and banks B. merchants and consumers C . merchants and banks D. merchants and a card network 38. Onp. 139, Evans and Schmalensee point out that Adobe's solution to the pricing problem in two - sided markets was to A. charge the same price to both readers and creators of PDF files B. give the service away to both readers and creators of PDF files to attain critical mass C . charge creators of PDF files but not readers of the files D. charge readers of PDF files but not creators of the files