According to the PMBOK® Guide (Project Management Body of Knowledge), specifically within the Project Cost Management knowledge area, the approved version of the budget is defined as follows:

Cost Baseline (Option D): This is the approved version of the time-phased project budget, excluding any management reserves, which can only be changed through formal change control procedures. It is used as a basis for comparison to actual results. It is developed during the Determine Budget process by aggregating the estimated costs of individual activities or work packages.

Resource Calendar (Option A): This identifies the working days and shifts on which each specific resource is available. It is an output of the Acquire Resources process and is used for scheduling, not for establishing the financial budget.

Scope Baseline (Option B): This consists of the approved Project Scope Statement, the WBS (Work Breakdown Structure), and the WBS Dictionary. While the WBS is an input to determining the budget, the scope baseline itself is used to measure scope performance, not financial performance.

Trend Analysis (Option C): This is a Data Analysis technique used in the Control Costs process to examine project performance over time to determine if performance is improving or deteriorating. It is a process tool/technique, not a budget output.

In PMI standards, the Cost Baseline is typically displayed as an S-curve, representing the cumulative values of the time-phased budget. Once management reserves are added to the cost baseline, the result is the total Project Budget.