Answer should be B.
Meat consumption across all income levels is the same. Eg. A person who earns 10K dollars and a person who earns 2K dollars consume the same amount of meat. The argument assumes that if income ( or per capita income ) rises meat demand will also rise.
B attacks this by saying that meat consumption is the same across all income levels and hence it wont make any difference to the demand for meat even if the country prospers and income rises.
Interested in OA.
Interesting logic. But one basic flaw. YOU CANNOT DOUBT THE FACT GIVEN IN QUESTION STEM.
The question stem says "with growing prosperity there is a steady increase in per capita consupmtion of meat"... B says something quite different. You should not interpret something from the statment which goes against the fact of the question stem.
Moreover, Now there is x income level and x1 consumtion.(which may be same across income level)
In future there will be X+d income level and X1+d1 consumtion. ( consumption will be higher, whether it is same or not across income groups does not mater)
The answer should be D.
Str of the argument is:
There will be a shortage so B will become an importer GRAIN.
D does not deny any fact from the question but it gives an alternative solution: B also can be a importer of MEAT. ( not grain)