Ian remains in a coma after a serious diving accident. He is still on medical life support because he is unable to breathe and his heart will not beat without assistance. The accident likely caused damage to Ian’s

medulla

Explanation:

Ian remains in a coma after a serious diving accident. He is still on medical life support because he is unable to breathe and his heart will not beat without assistance. The accident likely caused damage to Ian’s  medulla. The medulla oblongata is a part of the hind brain that is located at the brain stem and it is responsible for some autonomic functions such as breathing, swallowing, sneezing, heart and blood functioning.

answer; researchers typically cannot control people's sexual behaviors as would be necessary in an experiment;