Which of the following is not a natural ligand that binds to G protein​

A10-year-old girl suffered from a rare malignancy in her brain and around her spinal cord. she had surgery, and most of the tumor mass was removed, but residual tumor remained in the brain and around the spinal cord. the girl's doctors informed her parents that chemotherapy and radiation were possible treatment options but could cause serious problems such as sepsis, a permanent loss of iq and stature, and even death. the parents wished to proceed with the therapy. while their child was undergoing aggressive chemotherapy and radiation, the parents did independent research and read of several drugs being administered for cancer in other states that were unapproved by the federal drug administration (fda) and were illegal in their home state but were touted by physicians using them as miracle cures." furthermore, one of the girl's doctors released the girl's medical records to another physician to get a "second opinion" without informing the parents. this particular physician is a member of the same country club as the parents. he happens to share facts from the medical records with other members who end up telling the girl's parents. the couple sued their child's physician for failure to disclose alternative treatments, thus depriving them of informed consent. the couples also sued the child's physician for sharing their daughter's records in violation of the girl's privacy. how should the court rule in both cases? did the child's physician involved follow the law? did he act ethically in either situation? explain your answer. under the doctrine of informed consent, should a physician be responsible for informing patients of all treatment options, even if some of the treatments are illegal or not yet proven effective?