Identify the bias in the following surveys and explain the effect it could have on their results:

a, Parents of high-school students were asked: “Do you think that students should be released from school a half hour early on Friday, free to run around and get into trouble?”

b, Audience members at an investment workshop were asked to raise their hands if they had been late with a bill payment within the last six months

c, A random survey of corporate executives asked: “Do you favour granting a cable-television license for a new economics and business channel?”