Which of the Following Bonds Would Be Considered 'Investment-Grade' Bonds

Which of the following bonds would be considered 'Investment-Grade' bonds?
I. A Government of British Columbia bond rated 'AA'
II. A Government of Canada bond rated 'BBB'
III. A Municipality of Red Deer bond rated 'Baa'
IV. A Regional Municipality of Niagara bond rated 'AA'

A) I) only.
B) I) and IV) only.
C) I) , II) , and IV) only.
D) II) and III) only.
E) All are 'Investment-Grade'.