Which of the followingscenarios contains asampling error?

Select the correct answer below:

A study is conducted to determine thefavorite subject of all the students in your high school. Students in your homeroom class were used as the sample.

A study is conducted about where the best travel destinations are - Europe or Asia. People who live in big cities throughout Europewere used as the sample.

A hospital conducts a study about a new heart monitoring software. Somepatients who use the software wereused as the sample.

A study is conducted by a cereal manufacturer about two brands of cereal, andaquestion on a survey read,"Do you prefer the delicious taste of Brand X or the taste of Brand Y?"