We would reject the null if a p-value of less than 0.05 were obtained. I'm not sure if this answers your question; couldn't tell if you were asking about the significance level or wanted to clarify the topic questions.
So 60 labs decided to group up to test the null hypothesis (sample mean is equal to zero) against the alternative (sample mean is not). The 60 labs collect 10 samples each and all use an α = 0.05 level. Assuming the null hypothesis is true:
a) Probability that no labs reject the null?