A metal rod with a length of $80\,\text{cm}$ is pivoted at point $O$. Its centre of mass lies at its midpoint. Four pulley wheels are labelled with the letter $P$. As shown, the rod is in equilibrium. What is the weight of the rod?
- A$0.20\,\text{N}$
- B$1.0\,\text{N}$
- C$2.0\,\text{N}$
- D$4.0\,\text{N}$