Just needed some points :)
North i think because you going up
Lines of latitude (parallels) run east-west around the globe and are used to measure distances NORTH and SOUTH of the equator. Since the equator is 0 , the latitude of the north pole, 1/4 of the way around the globe going in a northerly direction, would be 90 N.
I believe the answer is B
The researchers kept their identities secret because, if they had revealed that their purpouse was to conduct an experiment on the behaviours of the people in the bar, it might have triggered that some people changed their usual attitudes because they know that their 'figures' will be kept in a record.
Maybe some people will drink less as they feel embarrased if some other person is testing how many beers they end. Others, might want to prove themselves 'strong' and drink much more than usual. People change their behaviour sometimes when they are aware that they are watched. This is called the observer effect.
Why 21 years old is the age limit for drinking alcoholic beverages Because, scientist claim it is the age the brain is fully grown and is ready for alcohol. :)