Question

read the passage.
do you speak baseball?
if you watch a professional baseball game attentively, you will see a subtle game within
the game: a sequence of wordless signals passing among members of a team. these
seemingly arbitrary gestures—a player scratching his nose and then tapping his right
forearm, a coach tugging his cap three times in succession—are actually a secret, closely
guarded code to communicate strategy within the team. an adjustment of a cap might be
an instruction for a batter to bunt the ball; a hand in the back pocket could indicate that a
player should steal a base. as you might expect, opposing teams expend enormous effort
to crack each other’s codes. for this reason, teams not only change their codes often but
also intersperse meaningless decoy signals with the real ones, just to confuse the
opposing team.
what is the main, or central, idea of the passage?
to maintain secrecy, baseball players and coaches must adapt the codes that
they use.
baseball players and coaches use secret signals to communicate strategy to
each other.
baseball players and coaches spend quite a bit of time trying to crack other
teams’ codes.

Explanation:

The passage first describes that baseball players and coaches use secret, wordless signals (like scratching nose, tapping forearm, tugging cap) to communicate strategy. Then it mentions opposing teams try to crack these codes, so teams change codes and use decoy signals. But the main idea is centered around the use of secret signals for strategy communication, with the other points (adapting codes, cracking codes) being related details or consequences of the main practice of using secret signals. The first option focuses on adapting codes (a secondary point), the third on cracking codes (also secondary). The second option captures the core action of using secret signals for strategy communication.

Answer:

B. Baseball players and coaches use secret signals to communicate strategy to each other.