You Plan to Conduct a Research Project in an Elementary

You plan to conduct a research project in an elementary school. Which of the following is a permissible way to obtain parental informed consent?

A) Send a form to parents that fully explains the research and ask them to respond only if they do not want their child to participate.
B) hold a face-to-face meeting with the parents to explain the nature of the research and obtain their consent.
C) send a consent form to parents that fully explains the research and inform them their child will participate only if they sign and return the consent form.
D) a and c, but not b.