Which of these is an example of a non-random sample?
A.
At a school assembly, five students are randomly chosen to receive free admission to a theme park.
B.
Out of all the seventh grade students in a public school district, fifteen are chosen to win a trip to a vacation destination.
C.
Registered voters in Arizona are surveyed to determine if they have relatives in Florida.
D.
Airline passengers to Orlando, Florida, are asked about vacation plans.