Final answer:
The detail from the text that best supports the statement is that Douglass did not reveal the names of those who taught him to read to protect them from potential consequences.
Step-by-step explanation:
The detail from the text that best supports the statement that Frederick Douglass did not name those who helped him learn how to read to protect his teachers is: 'but prudence forbids;—not that it would injure me, but it might embarrass them.' The detail from the text that best supports the statement is that Douglass did not reveal the names of those who taught him to read to protect them from potential consequences.
This detail shows that Douglass was aware of the consequences of teaching slaves to read and wanted to protect those who helped him by not revealing their names. It highlights the fear and opposition that slaveholders had towards educating enslaved individuals.