Asample is best defined as
a. a group of participants in a study that is atypical of the larger population
b. the total of all possible cases from which a population is selected
c. a selected group of participants that is representative of a larger population
d. a group of participants in a study who have sampled the treatment condition

In Statistics, a data sample is a set of data collected and/or carefully chosen from a statistical population by a defined procedure. Normally, the population is very huge, constructing a census or a whole enumeration of all the values in the population is either unreasonable or intolerable. The sample usually signifies a subset of controllable size. Samples are collected and statistics are intended from the samples so that one can make implications or extrapolations from the sample to the population. So the answer is letter c.