The Compare Baselines page within the new Project Workspace is the designated feature for analyzing financial performance over time. It allows a project manager to take a snapshot of the initial plan (the baseline) and compare it against the current planned costs, actuals, and forecasts. This comparison is presented in a time-phased grid, enabling a clear month-over-month analysis of variances between the original budget and the latest financial data, which is the exact requirement stated in the question.

A. Using the Cost plan breakdown form: This form displays the detailed fiscal period breakdown for a single cost plan, not a comparison between the current plan and a historical baseline.

B. Using the Financials Cost page: This page provides a summary of the project's current cost plans and actuals but does not offer the specific functionality to compare these against a saved baseline.

D. Using the project Details page: This page shows high-level project attributes, status, and metadata. It does not contain detailed financial comparison tools or time-phased cost data.

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1. ServiceNow Product Documentation: Compare project baselines in Project Workspace. This document explicitly states, "Compare the current cost and benefit plan values of your project with a selected baseline to view the variance... The comparison is shown in a time-phased grid for the selected fiscal period." This directly supports the use of the Compare Baselines page for month-over-month comparison.

2. ServiceNow Product Documentation: Financial planning for projects and demands in Project Workspace. This guide details the financial management capabilities within the workspace, highlighting the "Compare Baselines" action as the method for tracking performance against the original plan.

3. ServiceNow Product Documentation: Create a project baseline in Project Workspace. This document defines a baseline as "a snapshot of the project's cost plan, benefit plan, and all the planned dates... at a specific point in time." This confirms that the "initial planned costs" are stored in a baseline, which is then used for comparison.