What does a SPI value greather than 1.0 indicates?

A.
Most work was completed than planned
B.
Less work was completed than planned
C.
Cost overrun for completed work has occurred
D.
Cost underrun for completed work has occurred
Explanation:
Schedule performance Index (SPI) = EV/PV is an indicator whether the project is on time (SPI = 1) or behind the schedule(<1)