Final answer:
The standard of deliberate indifference in Farmer vs. Brennan (1994) requires prison officials to act with conscious disregard of a substantial risk of serious harm to a prisoner's health or safety.
Step-by-step explanation:
The U.S.S.C. ruling that defines the standard of deliberate indifference according to Farmer vs. Brennan (1994) is based on the Eighth Amendment of the U.S. Constitution, which prohibits cruel and unusual punishment. In this case, the Supreme Court held that in order to establish a claim of deliberate indifference, a prisoner must show that the prison officials acted with a conscious disregard of a substantial risk of serious harm to the prisoner's health or safety. This means that prison officials must have knowledge of the risk and choose to ignore it.