Which element is defined as a reportable variable regarding planned, projected, and estimated dates?

The correct choice addresses the concept of a reportable variable concerning planned, projected, and estimated dates, which typically falls under the definition of "Condition." In the context of project management, particularly in tools like Adobe Workfront, "Condition" captures the various states of a project or task over time. It allows for monitoring how the actual progress compares with the planned timelines and whether any deviations are occurring.

This definition is key for stakeholders to ensure that deadlines are being met and to manage expectations effectively. The use of the term "Condition" signifies a higher-level overview of the project’s status in relation to time, allowing users to report on and analyze the project's performance dynamically.

The other choices do relate to aspects of project management but are not as closely tied to the reporting of dates. "Status" typically refers to the immediate state of a task or project rather than focusing on date variables. "Progress status" emphasizes current achievement against the planned work, and "Assignment status" relates more to the specific allocation and workload of team members rather than the overarching timeline aspects of the project. Thus, the choice of "Condition" as the reportable variable for dates aligns perfectly with the requirements of the question.