In Response to a Wave of Mass Killings, a Political

In response to a wave of mass killings, a political psychologist sets up an online study to examine attitudes towards gun control in the United States.The study involves collecting a sample of 40,000 Internet users recruited throughout all 50 states using advertisements on political discussion and news sites and including an equal number of men and women and an equal number of supporters of the two main political parties.The survey shows that a large majority favour tighter gun controls.Which of the following statements is false?

A) This is a longitudinal study because it follows a wave of killings.
B) This study has some similar characteristics to the Literary Digest study conducted in the 1950s.
C) Although the study may not tell us what the level of support for gun control is it could still be useful for studying relationships between variables.
D) With a clear sampling frame this design could be adapted to use probability sampling.
E) It is not clear from the description what the independent variables are.