Football is, I believe, the most popular game in England: one has only to go to one of the important matches to see this. Rich and poor, young and old, one can see them all there, shouting for one side or the other.
To a stranger, one of the most surprising things about football in England is the great knowledge of the game which even the smallest boy seems to have. He can tell you the names of the players in most of the important teams. He has pictures of them and knows the results of large numbers of matches. He will tell you who he expects will win such and such a match, and his opinion is usually as good as that of men three or four times his age.
Most schools in England take football seriously — much more seriously than nearly all European schools, where lessons are all that are important, and games are left for the children themselves. In England, it is believed that education is not only a matter of filling a boy's mind with facts in the classroom, education also means the training of character; and one of the best ways of training character is by means of games, especially team games, where the boy or girl has to learn to work with others for his team, instead of working for himself alone. The school therefore plans games and matches for its pupils. Football is a good team game, it is good both for the body and the mind. That is why it is every school's game in England.
In the first sentence, by "this" the author means ______.

A.people often go to a football game

B.people, rich and poor, young and old, play football

C.football is the most popular game in England

D.people usually shout at each other in a football match