The Rankine scale starts at?

The Rankine scale is an absolute temperature scale used primarily in engineering and thermodynamics, and it is based on the concept of absolute zero. The starting point of the Rankine scale is indeed 0°Rankine (°R), which is equivalent to 459.67°F below the freezing point of water. This translates to the fact that 0°R is 459.67°F, and when this is expressed in terms of how far it is below the freezing point, we see that it starts at 459.67°F below that point.

Concisely, the correct choice identifies that the Rankine scale starts at a temperature 492 degrees below the freezing point of water when accounting for the standard freezing point of water at 32°F. Hence, option C captures the concept that 0°R is effectively indicating a temperature that is significantly low relative to common temperature measurements, aligning closely with engineering contexts where such calculations are crucial.