A rigid lever arm shaped like an L is mounted so that it pivots about point P. As shown in the diagram, three forces are applied to the lever arm. What is the magnitude of the resultant moment of these forces about point P?
- A$15\,\text{N m}$
- B$20\,\text{N m}$
- C$35\,\text{N m}$
- D$75\,\text{N m}$