Before asking people to participate in a research project, an investigator must provide them with a document providing __________.

A) a meta-analysis
B) debriefing
C) open practices
D) informed consent

Informed consent is the document that an investigator must provide to participants in a research project. It outlines the purpose and procedures of the study, potential risks and benefits, confidentiality, and the participant's right to withdraw from the study at any time. It also requires participants to provide their voluntary agreement or consent to participate. A meta-analysis is a statistical technique used to combine and analyze data from multiple studies. Debriefing refers to providing participants with information about the purpose and results of a study after they have completed it. Open practices refer to a research approach in which raw data and research materials are made publicly available for other researchers to use and replicate.