Consider a particle moving in a circular path. If $$r$($t$)$ is the radial unit vector and $$$($t$)$ is the transverse unit vector, which of the following correctly represents the time derivative of $$r$($t$)?$

d$$r$($t$)/$dt $=-$$($t$)$$($t$)$

d$$r$($t$)/$dt $=$ $($t$)$$($t$)$

d$$r$($t$)/$dt $=$ $($t$)$r$($t$)$

d$$r$($t$)/$dt $=-$$($t$)$r$($t$)$