But does he know that, for example, Quebec's Unibroue, the micro-brewery Quebeckers are so proud of because it produces a quality beer that is sold all over the world, is unable to sell a single bottle of beer in Ontario because of the tariffs and structures the Ontario government has put in place to keep out producers from Quebec and, I suppose, from other provinces also?
Quebec's Unibroue sells the largest volume of beer in Canada. 
Quebec's Unibroue is unable to sell a single bottle of beer in Ontario but the author does not state for sure whether it is sold in other provinces or not. Thus, it could be the largest volume in all of Canada.
( z1 sell :ARG0 ( z2 company :name ( z3 name :op "Unibroue" ) :mod ( z4 province :name ( z5 name :op "Quebec" ) ) ) :ARG1 ( z6 beer :quant ( z7 volume :ARG1-of ( z8 have-degree :ARG2 ( z9 large ) :ARG3 ( z10 most ) :ARG5 ( z11 volume :quant-of ( z12 beer :location ( z13 country :name ( z14 name :op "Canada" ) ) ) ) ) ) ) )