Commercial data communications monitors (software tools for analyzing protocol traffic and sessions) include which of the following?

Introduction / Context:
A data communications monitor is software that observes, captures, and analyzes traffic and protocol exchanges—often used for troubleshooting, performance tuning, or session auditing. Historically, various commercial tools targeted mainframe, minicomputer, and LAN environments to decode and summarize sessions across terminal and network protocols.

Given Data / Assumptions:

• We are identifying examples of software products (not carriers or generic terms).
• Legacy/mainframe ecosystems had proprietary monitoring suites.
• Only one option is to be selected as the best-known example.

Concept / Approach:
Among the listed names, ENVIRON/1 is a recognized commercial communications monitor package from historical enterprise environments. The other choices either do not clearly map to established monitoring products or refer to a service provider rather than a software monitor.

Step-by-Step Solution:

Verification / Alternative check:
Historical catalogs and enterprise software references list ENVIRON/1 among communications/transaction monitors. The other labels are ambiguous or unrelated to monitoring software.

Why Other Options Are Wrong:

Common Pitfalls:
Confusing service/network brands with software tools; assuming any acronym implies a monitor. When in doubt, prefer the option with clear historical association to comms monitoring.

Final Answer:
ENVIRON/1.