The British often used a "mask" to keep their messages secret. Hidden within what looked like an ordinary letter was the secret message that was only revealed when the reader applied the mask. The writer might send the letter by one rider going by one route while another rider carried the mask on another route. Such letters had an extra advantage: The writer could include false information in case Americans intercepted the letter.

Question

—George Washington, Spymaster,
Thomas B. Allen

Which statement best states the central idea?

A mask was a way to decipher messages.
Letter writers could travel via several routes.
Writers could include false information.
A mask was needed to send a message.

Answer 1

The statement that best states the central idea is:

A mask was a way to decipher messages.

This captures the essence of the secretive method used by the British to keep their communications private.