The potential energy of a conservative system is given by\[\operatorname{U} = a{{y}^{2}}-by\], where y represents the position of the particle and a as well as b are constants. What is the force acting on the system?

• A. \[-ay\]
• B. \[-by\]
• C. \[2ay-b\]
• D. \[\operatorname{b}-2ay\]