A ruler of length $0.30\,\text{m}$ is supported at its midpoint. Forces of equal size, $2.0\,\text{N}$, act in opposite directions at the two ends of the ruler, producing a couple as shown. What is the magnitude of the torque of the couple on the ruler in the position shown?
- A$0.23\,\text{N m}$
- B$0.39\,\text{N m}$
- C$0.46\,\text{N m}$
- D$0.60\,\text{N m}$