A large number of randomized experiments were conducted to determine whether taking a particular drug regularly would decrease the chance of getting a certain disease. For each of the experiments, the drug effect is the difference between the proportion of people taking the drug who got the disease and the proportion of people taking a placebo who got the disease. If the drug had no effect whatsoever, which of the following experimental results would be anticipated?

1. p-values will be greater than 0.05 for about 95 percent of the experiments.
2. There will be about an equal number of experiments showing positive and negative values of drug effect.
3. When 95 percent confidence intervals for the population drug effect are constructed, those confidence intervals include 0 about 95 percent of the time.

I only

II only

III only

I and II only

I, II and III