Final answer:
The population is all adults in the United States, while the sample is the 1500 adults who were surveyed.
Step-by-step explanation:
In the survey in question, the population denotes all individuals to whom the results are intended to be generalized, which in this case is adults in the United States. On the other hand, the sample refers to the actual group of individuals from the population who participated in the survey. Out of the options provided, the correct answer is B: Population: Adults in the United States, Sample: 1500 adults.