A Researcher Creates an Online Survey to Measure Flaming (Aggressive

A researcher creates an online survey to measure flaming (aggressive commentary) on the Internet.The survey is distributed by mailing a web link to randomly selected users of the largest social media service in the United Kingdom, Canada, Australia and Israel.The survey is in English and is sent to 3200 users with a 25% return rate.The questions include "Are you a troll?" and "Do you flame people for fun or do they just deserve it?" as well as a standard inventory measuring aggression.The researchers conclude that flaming is higher in the United Kingdom but aggression is higher in Australia.Which of the following statements is true?

A) The survey uses a standard inventory so it should be possible to estimate standard errors
B) The survey uses a probability sampling method
C) We could conclude whether the survey uses a probability sampling method if we knew how many users each social media service has.
D) We could conclude whether the survey uses a probability sampling method if we knew how many people live in each country.
E) We could conclude whether the survey uses a probability sampling method if we knew how many people who live in each country use social media services