The diagram depicts two fixed pins, Y and Z. An elastic band is stretched from Y to Z and passes around pin X, which is connected to a trolley. X lies at the midpoint of the elastic, and the trolley is to move in the direction P, perpendicular to YZ. The tension in the elastic is $4.0\,\text{N}$. What force accelerates the trolley in the direction P when it is released?
- A$2.4\,\text{N}$
- B$3.2\,\text{N}$
- C$4.8\,\text{N}$
- D$6.4\,\text{N}$