The correct answer is: C. Jain
Santhara is a religious ritual of Jainism. It is a voluntary fasting to death, practiced by Jains who believe that it is the most compassionate way to end their lives. Santhara is not suicide, as it is not motivated by despair or a desire to escape suffering. Rather, it is seen as a way to achieve moksha, or liberation from the cycle of rebirth.
Sikhs, Jews, and Buddhists do not have a religious ritual similar to santhara. Sikhs believe in reincarnation, and they believe that it is their duty to live a good life and help others. Jews believe in an afterlife, and they believe that it is their duty to live a good life and follow the commandments of God. Buddhists believe in reincarnation, and they believe that it is their duty to live a good life and follow the Eightfold Path.
Santhara is a controversial practice, and it is illegal in some countries. However, it is still practiced by some Jains, who believe that it is a way to achieve moksha.