Final answer:
Interviewing all of your teachers to collect their opinions on the last contract settlement is an example of a census since it surveys the entire group of interest.
Step-by-step explanation:
To collect opinions on the last teacher contract settlement, interviewing each one of your teachers would be an example of a census. This is because a census involves collecting data from every member of a population. In contrast, random sampling involves selecting participants through a process that gives each individual in the population an equal chance of being chosen. Whereas, convenience sampling is based on the ease of access to participants and often results in biased data. In this case, since all the teachers are being interviewed, it's a full survey of the available population, which is precisely what a census entails. Therefore, the correct response is B. a census.