At the dsl local carrier's office, the demultiplexes the data streams and converts them into digital data.

At the DSL (Digital Subscriber Line) local carrier's office, the  DSLAM demultiplexes the data streams and converts them into digital data.

DSLAM stands for Digital Subscriber Line Access Multiplexer. It is a network device, usually at a telephone company central office that aggregates individual subscriber lines  into a high-capacity uplink.

d. local area network (lan)

explanation:

a local area network (lan) is a collection of computers it connected to one another or to a common connection medium.

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