The stress levels of students during an exam were measured in three different testing environments: (a) complete silence, (b) with music playing, (c) while their instructor was talking on his cell phone. The mean stress levels were 73.5, 82.5, and 91.3, respectively.The overall F-statistic was calculated as 14.08 with 2 and 42 degrees of freedom with an associated p-value of < 0.0001.What is the conclusion that we should make from this result?

1) We do not have sufficient evidence that the mean stress levels differ in at least two of the groups.

2) We have sufficient evidence that the mean stress levels differ in at least two of the groups.

3) We have sufficient evidence that the mean stress levels differ across all groups.

4) All of the means are the same.