A training organizations customers can register and pay for classes via credit card by using a Web
browser. Customers can also send questions and inquiries to the organization’s sales staff.
From the organization’s corporate headquarters, network administrators monitor and manage
devices throughout the corporate network. If there is a communication problem with any of these
functions, which layer of the ARPA. architecture is the likely cause?

A.
Application

B.
Data Link

C.
Network

D.
Transport