Which of the following scales of temperature has only positive degrees of temperature?

The absolute scale  temperature or Kelvin scale of temperature was suggested by Lord Kelvin. The Kelvin scale has ice point at  $273K$ and steam point at $373K$. Thus, any temperature ($t^{o}C$) on the Kelvin scale is given by $T=(t+273)K$.

Celsius or Fahrenheit scale may have positive or negative values. But a Kelvin scale will have only positive values on the temperature scale.