Respuesta :
Answer:
A or D.
Step-by-step explanation:
a. It is a valid sample because the first eight people were selected to participate.
b. It is not a valid sample because it is not a random sample of the population.
c. It is a valid sample because money was offered to participants.
d. It is not a valid sample because it is only a short study.
are these your choices?
if so, I would say A or D.