Well once someone takes an antibiotic, their nervous system is able to fight eventually and that antibiotic wont help anymore so multidrug-resistant TB is formed because you do not have any antibiotics to protect you from it.
False sports drinks are supposed to last up to 2 hours
The magnetic field of a bar magnet is the strongest at either pole of the magnet. It is equally strong at the North Pole when compared with the south pole. So I would say the answer is A.