A population is the entire group that you want to draw conclusions about. A sample is the specific group that you will collect data from.
From the question, the 10 people that are being surveyed are referred to as the sample.
While a parameter is a fixed measure describing an entire population (a mass of all units under consideration that shares common characteristics) based on all the elements within that population, a statistic is a characteristic of a sample.
From the question, the survey results will give us the statistic: the flavors of soda the sample enjoys. From the survey results can be gotten the parameter, an extrapolation of the sample survey results for the entire population of 50.