Please answer a question about the following article about Brigham Young University:

In 1903, Brigham Young Academy was dissolved, and was replaced by two institutions: Brigham Young High School, and Brigham Young University. (The BY High School class of 1907 was ultimately responsible for the famous giant "Y" that is to this day embedded on a mountain near campus.) The Board elected George H. Brimhall as the new President of BYU. He had not received a high school education until he was forty. Nevertheless, he was an excellent orator and organizer. Under his tenure in 1904 the new Brigham Young University bought 17 acres (69,000 m2) of land from Provo called "Temple Hill". After some controversy among locals over BYU's purchase of this property, construction began in 1909 on the first building on the current campus, the Karl G. Maeser Memorial. Brimhall also presided over the University during a brief crisis involving the theory of evolution. The religious nature of the school seemed at the time to collide with this scientific theory. Joseph F. Smith, LDS Church president, settled the question for a time by asking that evolution not be taught at the school. A few have described the school at this time as nothing more than a "religious seminary". However, many of its graduates at this time would go on to great success and become well renowned in their fields.

Who we responsible for the giant "Y" that is embedded on a mountain near the campus?
BY High School class of 1907