The power supplied to a television is $P_{\text{in}}$. The useful sound and light power produced by the television is $P_{\text{out}}$. What is the efficiency of the television?
- A$\dfrac{P_{\text{out}}}{P_{\text{in}}}$
- B$\dfrac{P_{\text{in}} - P_{\text{out}}}{P_{\text{in}}}$
- C$\dfrac{P_{\text{in}}}{P_{\text{out}}}$
- D$\dfrac{P_{\text{out}}}{P_{\text{in}} - P_{\text{out}}}$