Passage Summary: When we move the clocks forward and lose an hour of sleep, car crashes go up the next day, so it is probably because people are tired.

Conclusion: Sleep deprivation is the likely cause of the 7 percent increase in traffic accidents following the start of daylight saving time.

Reasoning: The start of daylight saving time causes many people to lose an hour of sleep, and government data shows a corresponding spike in accidents the very next day.

Analysis: The argument jumps from a correlation (sleep loss and accidents happening at the same time) to a causal claim (sleep loss caused the accidents). To strengthen this, we need to bolster that causal link or eliminate other potential causes. Look for an answer that shows the spike doesn't occur in situations where the time changes but sleep isn't lost, or one that rules out other variables like changes in morning light or driving patterns.