To determine the Cost Variance (CV), we must first identify the key Earned Value Management (EVM) metrics provided in the scenario based on the PMBOK® Guide:

Planned Value (PV): The authorized budget assigned to scheduled work. Since the work was scheduled to be finished today, $PV = \$1,000$.

Actual Cost (AC): The realized cost incurred for the work performed. The scenario states the expenditure is $AC = \$1,200$.

Earned Value (EV): The measure of work performed expressed in terms of the budget authorized for that work. Since approximately half (50%) of the work is completed, we calculate EV as:

$$EV = \text{Budget at Completion (BAC)} \times \text{Percentage Complete}$$

$$EV = \$1,000 \times 0.50 = \$500$$

The Formula for Cost Variance (CV) is:

$$CV = EV - AC$$

Calculation:

$$CV = \$500 - \$1,200 = -\$700$$

Interpretation according to PMI Standards:

A negative CV indicates that the project is over budget relative to the work performed. In this case, the work package is $700 over budget.

Choice A is the correct calculation.

Choice B (-200) is the result of $PV - AC$, which is not a standard EVM variance formula.

Choice C (200) is the absolute difference between PV and AC, ignoring the actual work completed (EV).

Choice D (500) represents the EV itself, not the variance.