Hello. You did not present the excerpts of the letter to which the question refers, for this reason, I will answer the questions taking the entire letter into consideration.
A. One of the purposes of the letter was to show how much it was necessary for the population to support movements in favor of women's suffrage. The authors of the letter showed how suffrage was a right that was being denied to women and how it was damaging to the entire population, but mainly women who did not have any representation and therefore lived at the mercy of policies that did not favor them.
B. The letter was aimed at reaching a male audience, which was the marjoritary audience of Seneca County Courier. The objective was to get the male population to decide to help in the cause that the suffragettes were organizing. In addition to showing that female suffrage would not harm men, but would benefit everyone.
C. The text shows the impact of education on the American female population. This is because women began to question their political representation, after women began to have access to formal education, especially middle-class women. This gave women greater knowledge of politics, social position, classes, rights and laws. In addition, education allowed them to write texts, letters and organize protests in favor of this cause.