What is the Big$-$O for sequential search when the data is not in order $($random data$)?$

A$.$ O$(1)$

B$.$ O$($log n$)$

C$.$ O$($n$)$

D$.$ O$($n$*$log n$)$

E$.$ O$($n$^2)$

F$.$ O$($n$^3)$

G$.$ O$(2^$n$)$

H$.$ none of the above