"Congress Passed a Ban on the Sale of Assault Weapons

"Congress passed a ban on the sale of assault weapons. Now there is a move to repeal that ban. Do you agree that the ban on sale of assault weapons should be repealed?" That question is asked in an SRS of 1000 adults in Texas (population 18 million people) and a separate SRS of 1000 adults in Indiana (population 5.7 million people) . Ninety-five percent confidence statements are made about the percents of all adults in both states who agree.
It would be cheaper to just announce the question on TV and ask people to call in with their opinions. Is this the best approach?

A) This is a good way to get information about the opinions of all adults.
B) This is a bad idea because if only a few people call in, the margin of error will be large.
C) This is a bad idea because allowing people to volunteer may result in large bias.
D) This is a bad idea because those who call in would not be a sample.
E) This is a bad idea because those who call in would not be a population.