A researcher posts a magazine advertisement offering $24 in exchange for participation in a short study. The researcher accepts the first six people who respond to the advertisement. Which of the following statements is true about the sample? It is not a valid sample because it is not a random sample of the population. It is a valid sample because the first six people were selected to participate. It is a valid sample because money was offered to participants. It is not a valid sample because it is only a short study plz answer asap! will give brainliest answer no explanation needed plz make sure ur 100 percent correct plz answer asap