If \(\overrightarrow{r}=(\cos nt)\overrightarrow{a}+(\sin nt)\overrightarrow{b}\), then \(\frac{d\overrightarrow{r}}{dt}\times \overrightarrow{r}=\)
1
\(n(\overrightarrow{b}\times\overrightarrow{a})\)
2
\(n(\overrightarrow{a}\times\overrightarrow{b})\)
3
\((\cos nt+\sin nt)(\overrightarrow{b}\times\overrightarrow{a})\)
4
\((\cos nt+\sin nt)(\overrightarrow{a}\times\overrightarrow{b})\)