The first crossword puzzle was printed in an Italian newspaper in 1890. Since then, millions of people have enjoyed crosswords as simple entertainment or as a challenge to keep their minds sharp. In North America, crossword grids are composed of black and white squares, and squares within the puzzle are assigned a number that corresponds to a clue. In Sweden, squares within the crossword grid contain clues instead of numbers, and Japanese crossword puzzles always have white corner squares. The word "cruciverbalist" most often describes a person who composes crossword puzzles, but it can also refer to a fan of crosswords. In the U. S., cruciverbalists create crossword puzzle clues that vary from simple definitions to complex anagrams that require a thorough knowledge of the English language. More complex puzzles, such as the infamously difficult New York Times crossword, contain clues with obscure trivia facts. Modern crossword puzzle clues also contain popular culture trivia and colloquial words and phrases, such as "dude," "superfreak," or "what's up." Emerging research suggests that people who keep their minds active through crossword puzzles are less likely to suffer from memory loss and senile dementia.
The reader can conclude that
A.
crossword puzzles are harder in Sweden than in Japan.
B.
crossword puzzles adapt to changes in language.
C.
crossword puzzles reduce the risk of brain cancer.
D.
crossword puzzles were invented to amuse the elderly.