The best choice to complete the paragraph is B. "Sudoku, on the other hand, is just a logical exercise, each one similar to the last."
Explanation:
The paragraph contrasts crossword and Sudoku enthusiasts, emphasizing that crosswords require vocabulary, knowledge, and even humor, making them more dynamic and diverse. To maintain this contrast, the concluding sentence should highlight the perceived simplicity or repetitive nature of Sudoku.
Option B fits best because it reinforces the argument that Sudoku, unlike crosswords, is a purely logical exercise with a structured, repetitive nature. This aligns with the idea that some crossword enthusiasts see Sudoku as lacking depth.
Other options don't fit as well:
A introduces a new idea about popularity, which doesn't logically follow.
C is true but shifts the focus to accessibility rather than the crossword-Sudoku contrast.
D and E are too extreme and dismissive, making them weaker choices.
In GMAT-style critical reasoning questions, the correct answer should logically extend the given argument without introducing unrelated information or unnecessary subjectivity.