单选题：根据下面文章，回答题In a recent announcement, Harvard and the Massach

根据下面文章，回答题
In a recent announcement, Harvard and the Massachusetts Institute of Technology(MTT) said that they have joined forces to offer free online courses in an effort to attract millions of online learn- ers worldwide．
Beginning this fall, a number of courses developed by teachers at both universities will be of-fered online through a new MYM60 million program, known as edX．"Anyone with an Internet con-nection anywhere in the world can use our online courses," Harvard President Drew Faust said dur-ing a meeting to announce the plan．
MTT has offered a program called OpenCourseWare for ten years that makes materials from more than 2,000 classes free online．It has been used by more than 100 million people．In December, the school announced it also would begin offering a special certificate, known as MITx, for people who complete certain online courses．Harvard has long offered courses to a wider population through a similar program．
The MITx will serve as the foundation for the new learning platform．
MIT President Susan Hockfield said more than 120,000 people signed up for the first MITx course．She said Harvard and MIT hope other universities will join them in offering courses on the open-source edX platform．
"Fasten your seatbelts," Hockfield said．
Other universities, including Stanford, Yale and Carnegie-Mellon, have been experimenting with teaching to a global population online．
The Harvard-MIT program will be monitored by a not-for-profit (非盈利的)organization based in Cambridge, to be owned equally by the two universities．Both MIT and Harvard have provided MYM30 million to start the program．They also plan to use the edX platform to research how students learn and which teaching methods and tools are most successful．
According to this text, edX is__________． A．a part of the free MIT Open Course Ware
B．a free computer program by MIT and Harvard
C．a Harvard-MIT platform of free online courses
D．a free program online for universities worldwide