What is the runtime complexity notation for the following algorithm?

LowNum $($ListOfAgeGroups$,$ listsize,

myAge$)($

for $($etr $-0$; ctre

listsize:

#ctr$)($

$1$f $(1$istOfAgeGroups$[$ctr$)-=$

myAge$)$

return etr

O$(1)$

$$ O$($N$2)$

$$ O$($N$)$

$$ O$($N$-$logN$)$