$7)$ Which statement is FALSE regarding the location of the center of pressure $($COP$)?$ a$)$ The COP must lie within the base of support b$)$ The COP must lie within the contact area of the foot during single leg support c$)$ During standing, balance is maintained by locating the COP directly under the COG on average d$)$ During standing, the moment arm of the gravitational force is on average twice the COP distance from the same reference axis