The correct option is C n≥1
For n=1, we have n2−n+1=12−1+1=1 which is an odd number
For n=2, we have n2−n+1=22−2+1=3 which is an odd number
For n=3, we have n2−n+1=32−3+1=7 which is an odd number
For n=4, we have n2−n+1=42−4+1=13 which is an odd number
For n=5, we have n2−n+1=52−5+1=19 which is an odd number
Hence, n2−n+1=12−1+1=1 is an odd number for all n≥1