What is the main purpose of a code review?

While a technical lead might gain visibility, this is a secondary benefit; the primary goal is quality and error detection, not just visibility for one role.

Code reviews primarily serve as a quality assurance process where peers collaboratively inspect code to find defects, improve code quality, ensure adherence to standards, and share knowledge, ultimately identifying and reviewing errors as a team.

Code reviews are conducted before or during code submission, not to ensure simultaneous check-ins, which is an unrelated concept to quality assurance.

Detecting logical errors is a purpose of code review, but "identify and review errors with the team" (B) is a more comprehensive and accurate description of the main purpose, encompassing various types of errors and the collaborative aspect.