This 363-mile-long waterway, the longest canal in the US at the time, made it much easier to transport passengers and goods between New York and the Great Lakes. For this reason, ______
Which choice completes the text so that it conforms to the conventions of Standard English?
it is often called "the nation's first superhighway."
A
it is often called "the nation's first superhighway"?
B
is it often called "the nation's first superhighway"?
C
is it often called "the nation's first superhighway."