Every minute of every day, someone needs blood. that blood can only come from a volunteer donor, a person like you who makes the choice to donate. there is no substitute for your donation. when you make a blood donation, you join a very select group. currently only 3 out of every 100 people in america donate blood. from its beginning, the american red cross has formed a community of service, of generous, strong and decent people bound by beliefs beyond themselves. the american red cross blood donor embodies this principle. join us in our mission to maintain a safe and stable blood supply by making your appointment to donate blood today.
based on this excerpt, what is the author’s primary purpose for writing?

To convince  people that the Red Cross keeps blood safe and stable.

Explanation:

The persuasion is achieved by some explanation.The Red Cross makes it clear that blood donation is highly requested. The excerpt  sets the focus on the fact that the blood that is donated undergoes a hard process to keep it safe and stable. If someone donates his blood, this blood will not be replaced by somebody else's blood. A community  of service has been formed by the Red Cross to guarantee that the blood supply will be safe and stable.

source text: from the sketch here given it will be seen, that our good grandmothers differed considerably in their ideas of a fine figure, from their scantily dressed descendants of the present day. a fine lady, in those times, waddled under more clothes even on a fair summer's day, than would have clad the whole bevy of a modern ball room. nor were they the less admired by the gentlemen in consequence thereof. on the contrary, the greatness of a lover's passion seemed to increase in proportion to the magnitude of its object—and a voluminous damsel, arrayed in a dozen of petticoats, was declared by a low-dutch sonnetteer of the province, to be radiant as a sunflower, and luxuriant as a full blown cabbage. certain it is, that in those days, the heart of a lover could not contain more than one lady at a time; whereas the heart of a modern gallant has often room enough to accommodate half a dozen - - the reason of which i conclude to be, either that the hearts of the gentlemen have grown larger, or the persons of the ladies smaller — this however is a question for physiologists to determine. add punctuation to the following excerpt. writing under the name of diedrich knickerbocker washington irving aimed his potent satire at as diverse topics as political rivals such as thomas jefferson to the very ideal of looking back on the past affectionately: a fine lady, in those times, waddled under more clothes even on a fair summer's day, than would have clad the whole bevy of a modern ball room. a voluminous damsel, arrayed in a dozen of petticoats, was declared by a low-dutch sonnetteer of the province, to be radiant as a sunflower, and luxuriant as a full blown cabbage. in those days, the heart of a lover could not contain more than one lady at a time; whereas the heart of a modern gallant has often room enough to accommodate half a dozen