Final answer:
The practice of an IRS employee randomly selecting and checking 10 forms for mistakes is an example of random sampling, where each form has an equal chance of being chosen.
Step-by-step explanation:
When an IRS employee randomly selects and checks 10 forms for mistakes, this is an example of random sampling. Random sampling is a method where each member of the population has an equal chance of being selected. This differs from other methods like stratified, systematic, and convenience sampling, where the selection process involves dividing the population into subgroups or selecting individuals based on a predetermined pattern or ease of access, respectively.
Answer: a) Random sampling