In Earned Value Management (EVM), as defined in the PMBOK® Guide, the Variance at Completion (VAC) is a projection of the amount of budget deficit or surplus at the end of the project. It is expressed as the difference between the original budget and the current forecasted total cost.

The Formula:

$$VAC = BAC - EAC$$

Where:

$BAC$ (Budget at Completion) is the total planned budget for the project.

$EAC$ (Estimate at Completion) is the expected total cost of completing all work.

Calculation for this Question:

Given $BAC = 17$ and $EAC = 25$:

$$VAC = 17 - 25 = -8$$

Interpretation:

Negative VAC: Indicates a projected cost overrun. In this case, the project is expected to finish $8$ units over the original budget.

Positive VAC: Indicates a projected cost under-run (surplus).

Zero VAC: Indicates the project is expected to finish exactly on budget.

Analysis of other options:

B (425): This is the result of multiplying $25 \times 17$. Multiplication is not used in any standard EVM variance or index formula.

C (1.4): This is the result of dividing $25 / 17$ (or approximately $EAC / BAC$). While ratios like the Cost Performance Index (CPI) are used in EVM, $1.4$ does not represent the variance requested.

D (8): This is the absolute difference ($EAC - BAC$). While the magnitude is correct, the sign is vital in project management. A positive $8$ would incorrectly suggest the project is under budget, whereas the project is actually over budget.

Key Concept:

The Project Management Institute (PMI) emphasizes that Variance at Completion (VAC) (Choice A) is a critical forecasting tool for stakeholders. It allows the project manager to communicate the expected financial health of the project at its conclusion, enabling the organization to arrange for additional funding or adjust the scope to bring the project back toward its original financial goals.