Which of the following best describes sampling error?

Any given poll will result in as certain percentage point variation from the true answer as pollsters could not really interview everyone.

Researchers take a sample of voters and slant the results in order to influence future polls.

Researchers take a random number of people and survey them.

Pollsters make up the survey results.

Pollsters get a sample of people using demographic or geographical software to yield a high level of accuracy.