California has a new program called the Digital Textbook Initiative. "Starting this fall with high school math and science, we will be the first state in the nation to provide schools with a state-approved list of digital textbooks. " That was Governor Arnold Schwarzenegger in June,talking about his effort to get schools to use materials available free online. He listed reasons why he thinks digital textbooks make sense.
California approves traditional textbooks in six-year cycles. Digital ones can offer the latest information. They lighten the load of school bags. They save paper and trees, and make learning more fun and interactive. And above all, he said, they help schools with their finances.
The state has had to make severe cuts in school spending because of deep financial problems. More than six million students attend California public schools.
Earlier this year, California invited content developers to offer digital math and science materials for high schools. These had to meet at least 90% of the state's learning requirements.Specially trained teachers examined 16 textbooks and approved ten of them.
Six of the ten were published by the CK 12 Foundation, a nonprofit group that had been developing digital science and math books for about two years. The foundation paid teachers and other education professionals to write and edit them. The money came from a group financed by the Khosla Family.
California cannot require schools to use the digital textbooks. Individual school districts will have to decide for themselves.
Susan Martimo, a California Department of Education official, says she does not expect widespread use right away. Her best guess is that some schools with a lot of technology will be the first to use them, but only in addition to their traditional books.
School administrators point out that the texts may be flee online, but students need a way to access them. Not everyone has a computer or electronic reader. Schools could print out copies, but that would not help the environment. Also, there is the cost to train teachers to use digital textbooks effectively.
The Digital Textbook Initiative ______.

A. will probably take effect in six years
B. covers all the high school subjects
C. has been approved by all states
D. is advocated by California state governor