Identify the type of sampling bias guaranteed to occur in each of the sampling schemes, based on the information provided. some sampling schemes may incur multiple types of bias

a political poll is conducted by contacting people on landline phones. the pollsters did not keep track of how many people they contacted who did not respond.
a political poll is administered by contacting people on landline phones. the pollsters contacted 10,000 households, and 2366 individuals agreed to speak with the caller.
a political poll is conducted by allowing users to register on a website and fill out an online survey.
a political poll asks the question, "if you found out that candidate a was arrested when he was younger, would that change your opinion of how immoral candidate a is? "