A star’s power output $P$ may be represented by $P = \sigma A T^4$, where $\sigma$ is a constant, $A$ denotes the star’s surface area, and $T$ is the star’s surface temperature. Which SI base units does $\sigma$ have?
- A$\text{kg s}^{-2}\,\text{K}^{-4}$
- B$\text{kg s}^{-3}\,\text{K}^{-4}$
- C$\text{kg m}^{-1}\,\text{s}^{-2}\,\text{K}^{-4}$
- D$\text{kg m}^{-1}\,\text{s}^{-3}\,\text{K}^{-4}$