1812) Three key services provided at the application layer include: (1) synchronizing the services between a user application and the protocol(s) it may use, (2) ensuring that necessary resources required by an application service are available, and (3) ________. A) making sure that end users are receptiveB) making sure that the application is licensedC) making sure that email is properly set upD) making sure that the correct communication protocol or service is available to the application

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