For the discharge capacity of a temperature and pressure relief valve on a water heater, what is the minimum required rating relative to the water heater's input?

• Equal to or greater than the water heater's first-hour rating.
• As specified by the manufacturer's instructions only.
• Equal to or greater than the water heater's input rating in Btu/h.
• Equal to or greater than the water heater's storage capacity in gallons.