General Clinton, concerned about what General Howe was planning and doing, made use of a mask to write a secret message in a letter to General Burgoyne. Before writing the letter, Clinton had placed an hourglass-shaped mask on a piece of paper and then had formed the secret message within that shape.

The unmasked letter had enough false information in it to fool any American who happened to see it. But when Burgoyne viewed the letter with the mask, he read Clinton's view of the real situation: Howe has made a bad move; I don't have enough men to do anything about it.

The author’s main purpose in this excerpt is to

describe a form of code writing using an example.
explain the mistakes of General Howe during the war.
entertain the reader with a humorous story of miscommunication.
argue that using a mask is the best method for sending secret messages.

The author’s main purpose in this excerpt is to describe a form of code writing using an example.

Explanation:

In the text in question, the author describes how General Clinton inserted a secret message in a text apparently unrelated to the information that he wanted to convey. That is, through a real situation, he exemplifies how a secret message could be introduced that changed the course of history.

explanation:

dear evan hansen is a stage musical with music and lyrics by benj pasek and justin paul, and book by steven levenson.

the musical opened on broadway at the music box theatre in december 2016, after its world premiere at the arena stage in washington, d.c., in july 2015 and an off-broadway production at second stage theatre from march to may 2016.

at the 71st tony awards, it was nominated for nine awards, winning six, including best musical, best score, best actor in a musical for ben platt, and best featured actress in a musical for rachel bay jones.

the answer to "what does the narrator realize by the end of the story" is b.