Topic: web programming

Within the context of Web and REST APIs, which of the following statements are true?

a. The connectedness principle says that resource representations should not have links to related resources

b. The semantic gap can be narrowed by the use of model-based APIs

c. The resource state changes when the user performs an unsafe request such as POST or PUT

d. 4XX response codes are used when the request sent by the client cannot be understood by the web application

e. Model-based web APIs are considered a security risk because they give hackers knowledge of the application's relational model