Read this entry from a blog about service dogs.

Lexie, an eight-month-old black Labrador retriever, is sleeping quietly at my feet. I can’t help but think that her soft, velvety ears and alert brown eyes would make her the perfect “doggie model” for pet magazines and pet store ads. However, Lexie will soon have a much more important job to do. In a few months, she will become the loyal companion and service dog for a young man who has been blind since birth. She will help him board public transportation, such as buses, subways, and trains, and she will help him safely cross busy intersections. Lexie will even help the young man avoid obstacles, such as high curbs and low overhangs. Like all dogs in our organization, Lexie has undergone months of specialized training to help a visually impaired person lead an active and independent life.

Which statement about this blog is true?

Its primary purpose is to persuade; its secondary purpose is to inform.
Its primary purpose is to inform; its secondary purpose is to persuade.
Its primary purpose is to entertain; its secondary purpose is to persuade.
Its primary purpose is to inform; its secondary purpose is to entertain.