Which of the Following Is/are Indicators of the Trustworthiness of Qualitative

Which of the following is/are indicators of the trustworthiness of qualitative research from the standpoint of contemporary positivist standards?

A) The observation period should be short, so as to minimize social desirability bias.
B) Corroboration should exist among different sources of data.
C) Negative case analysis should be avoided.
D) All of the above.
E) None of the above.