A particle moves so that its position vector is given by r = cos ω t x + sin ω t y. Where ω is a constant. Which of the following is true?

A particle moves so that its position vector is given by $\displaystyle \vec{r}=\cos \omega t \hat{x}+\sin \omega t \hat{y}$. Where $\displaystyle \omega$ is a constant. Which of the following is true ?