Thank you all for your responses,
Professional1, I did write my country of residence. Iam applying inside Canada, but specifically the visa office name for Canada is Buffalo. So, I should have written Buffalo instead of Canada.
1. Do you think they will return it to me?
2. Should I send all the application again? What do you guys think?
I am residing in canada as well and i know that you are applying from within canada.
The question was, which visa office do you chose to process your application which is in the first page of your application after language you prefer for correspondence, it says exactly: "Visa office requested for the process of your application", and you wrote canada, that is wrong because their is no visa office called canada. The visa office which is responsible on applications for people who reside in canada is Buffalo, U.S.A, that is what you should have writen in the blank because the question is not asking for your country of residence, it is asking for the name of the visa office.
The answer is yes, if they opened your application they will send it back to you to fix it.
if you want to give it a try before they open the application send only a new copy of that page of the application after you adjust the name of the visa office, accompanied with an explanation letter.