Indicate all expressions represented by O$($n$)$

A: $5*$log$($n$)$ B: log$($log$($n$))$ C: n$/2+10$

D: n$*$log$($n$)$ E: $5$n $+100$ F: n$3+2$n$2+6$n$+24$

G: $1000$ H: n$*($n$+1)/2$ I: n