Which of the following are implications of Sawyer (2001)'s "A Market-Based Perspective on Information Systems Development"? Vendors now focus on developing products, not systems Software consumers and producers communicate their needs to developers via a variety of intermediated means, instead of through close direct links Vendors tend to be highly involved in implementation, leaving no room for intermediaries to support transactions between vendors and consumers Approaches to teaching Information Systems Development does not need to evolve with the market perspective The software product market gives rise to a software services market