When mailing out self-administered survey questionnaires, a sociologist forgot to include the informed consent paperwork. Why is this a violation of ethical processes? Select all that apply.
1) It violates the participants' right to informed consent
2) It compromises the confidentiality of the participants' responses
3) It undermines the trust between the researcher and the participants
4) It may lead to biased or inaccurate data
5) It is against the ethical guidelines set by research institutions