What is the biggest country in the middle east

That would be Saudi Arabia 

hope this helps :) 

Saudi arabia the total area is 2,149,690 and beats iran by 501,495

If the sample has the same size as the whole population, it's not a sample, but a full population! So it has to be smaller.

But it has to be recruited from the population, and it should also be representative of the population (have the same characteristics)- so the correct answer is "The sample must represent the target population"