In the context of DevOps.

The most effective approach to tool selection in DevOps is to establish a toolchain—a set of integrated tools that support the end-to-end lifecycle (planning, coding, building, testing, releasing, deploying, operating, and monitoring).

This encourages consistency, automation, and traceability, while still allowing flexibility for teams.

Why not standardize on one vendor?

This reduces flexibility, can cause vendor lock-in, and doesn’t support the varied needs of Dev and Ops teams.

Encouraging independent selection (C) increases fragmentation.

Focusing solely on testing (D) ignores the broader lifecycle.

Extract-style reference:

“Establishing an integrated toolchain provides end-to-end visibility and automation across the software delivery pipeline, aligning tools with process and cultural change.”

— State of DevOps Report; DevOps Handbook

PeopleCert DevOps Foundation v3.6: Recommends a toolchain approach for supporting collaborative DevOps practices.