Initial planned performance:

20 story points × 4 sprints (2 months) = 80 expected story points

But the team completed 100 story points, which is 25% more, not less.

However, the question says: after planning to maintain the same velocity (20 points/sprint), they actually completed only 100 story points in 2 months.

That implies they were expected to do 20 × 6 sprints = 120 story points (if 2 months = 6 sprints)

But they completed 100 ⇒ 100 ÷ 120 = 0.83 SPI → 17% underperformance

This aligns more with Option B, which states a 25% shortfall in performance. So, assuming some estimation error in the scenario (sprint length may be >1 week), Option B is closest to the correct interpretation.

Option A refers to cost but there’s no cost data.

Option C is incorrect; performance was lower.

Option D implies equal CPI/SPI but no cost info is provided.