Final answer:
The answer to the student's question is: a. representative.
Step-by-step explanation:
A sample that reflects the larger population in every important way is known as a representative sample. A representative sample accurately mirrors the demographics and other characteristics of the larger population. This includes factors such as sex, ethnicity, and socioeconomic status, among others. In contrast, a random sample is a subset of a population in which every member has an equal chance of being selected.
Regarding the effectiveness of random samples, the key advantage is that if the sample is large enough, it can be reasonably assumed to be representative of the population. This means that characteristics within the sample will have similar percentages to those found in the overall population, making the results from the sample more likely to be applicable to the population as a whole.