What is the main idea of this passage?

A. Scrabble is a popular and challenging board game.
B. There are several differences between the "in person" and online versions of Scrabble.
C. Scrabble takes a long time to play when you use a dictionary.
D. Scrabble is a game that only adults can enjoy playing.

B. There are several differences between the "in person" and online versions of Scrabble.