In computer communications, which device assembles groups of characters into complete messages before forwarding them to the CPU?

Introduction / Context:
In data communications, remote terminals and networks transmit characters or small blocks that must be framed into valid messages before a host computer can process them. Organizations often insert a specialized device between the network and the central processor to offload these chores and smooth traffic spikes.

Given Data / Assumptions:

• The question focuses on assembling groups of characters into complete messages.
• The target is a device positioned in front of the CPU on the communications path.
• We are contrasting this device with software tools like compilers, interpreters, and editors.

Concept / Approach:
A communications processor—commonly called a front-end processor (FEP)—terminates communication lines, handles character-level protocols, performs message framing, error detection/retransmission, and queue management, then passes complete messages to the host. Offloading these functions improves throughput and reduces CPU communication overhead.

Step-by-Step Solution:
1) Identify the required function: aggregate characters into full messages.2) Map known devices: compilers/interpreters translate code; editors modify text; multiplexers combine line signals but do not validate full messages.3) The device that frames, checks, and buffers messages for the CPU is the communications processor (FEP).4) Therefore, select the option naming the communications processor.

Verification / Alternative check:
Legacy mainframe architectures and modern network interface controllers echo this pattern: a dedicated front-end handles line discipline, freeing the host for application work.

Why Other Options Are Wrong:
Compiler/interpreter: translate source programs, not network messages. Editor: user text editing only. Terminal multiplexer: shares lines but does not assemble or validate complete application messages.

Common Pitfalls:
Confusing multiplexing with protocol handling; only the communications processor performs higher-level framing and error control for host delivery.

Final Answer:
A communications processor (front-end processor).