Answer:
Simple random sampling
Step-by-step explanation:
Simple random sampling is a subdivision of a sample chosen from a population. Individuals are randomly chosen by chance and each individual possess the same characteristics as every other person in the population. It is a a surveying technique that is unbiased.
The idea of this sampling method is that every object has an equal chance of being chosen.
If the researcher evaluates 200 students out of the population and make sure the sample reflects the population, the sampling method used is simple random sampling.