Informed consent in research with homeless youth is: A. Complicated and should involve parental or guardian consent unless waived by the courts
B. Often carried out with waiver of documentation when risk is no greater than minimal
C. Permitted with signed certificates of confidentiality given to each subject or their legal guardian
D. Allowed only with written parental permission when risk is no greater than minimal

Permitted with signed certificates of confidentiality given to each subject or their legal guardian  ( C )

Explanation:

An informed consent in research is required by law because it has to deal with sensitive issues and participation of minors. The competency of the minor or patient should be considered during an informed consent.

A homeless youth can be said to be fending for himself by himself hence he or she can be considered emancipated so an Informed consent in research with a homeless youth is  Permitted with signed certificates of confidentiality given to each subject or their legal guardian

  b.

there are isolated pockets of farming, generally around rivers and oases, which are used for irrigation.