Which of the following describes a painless procedure to help those with terminal illnesses?

The correct choice, euthanasia, refers to a medical practice in which a physician deliberately ends a person's life to alleviate suffering, particularly in cases of terminal illness where the individual is experiencing unbearable pain. This procedure is often characterized by its focus on providing a compassionate and humane end to life, allowing the individual to pass away without further distress.

In contrast, resuscitation involves attempts to restore life functions, which is not applicable in the context of terminal illnesses where the goal is to alleviate suffering rather than prolong life. Chemotherapy is a treatment intended to combat cancer through drugs, which can often lead to significant side effects and does not fit the description of a painless procedure. Surgery typically involves invasive procedures that can result in pain and require recovery time, which also makes it inconsistent with the concept of a painless ending to suffering in those with terminal diagnoses.