If you look at the stars, cutting off the rays (as may be done by looking through a very small hole made with the extreme point of a very fine needle, placed so as almost to touch the eye), you will see those stars so minute that it would seem as though nothing could be smaller; it is in fact their great distance which is the reason of their diminution, for many of them are very many times larger than the star which is the earth with water. –“In Praise of the Sun,”
Leonardo da Vinci

Which best identifies the author’s purpose?

to argue a theory about the size of stars
to inform readers about an experiment he conducted about stars
to entertain readers with a description of stars in the night sky
to argue a theory about the size of the Earth